Health Products Distributors

hyperhomocysteinemia

  • WHAT YOU NEED TO KNOW ABOUT VITAMIN B12

    Dr. Hank Liers, PhD vitamin B12 B-12 cobalamin methylcobalaminI previously wrote METHYLATION CYCLE, GENETICS, B VITAMINS in which I considered in-depth how the Methylation Cycle functions, how genetics affect metabolic pathways, and how B vitamins (including vitamin B12, folate, vitamin B6, and vitamin B2) are used in Methylation Cycle pathways. In today's article, I take an in-depth view of what you need to know about vitamin B12, including the effects of not having sufficient amounts of Vitamin B12 in the body.

    vitamin B12 Vitamin B12 contains the biochemically rare element cobalt positioned in the center of a chemical ring structure.

    Vitamin B12 is one of eight B vitamins. It is the largest and most structurally complicated vitamin. It consists of a class of chemically related compounds (vitamers), all of which show physiological activity. It contains the biochemically rare element cobalt positioned in the center of a chemical ring structure.

    Vitamin B12 (also called cobalamin) is a water-soluble vitamin that is involved in the metabolism of every cell of the human body. It is a cofactor in DNA synthesis, and in both fatty acid and amino acid metabolism. It is particularly important in the normal functioning of the nervous system via its role in the synthesis of myelin and in the maturation of developing red blood cells in the bone marrow.

    YOUR NEED FOR VITAMIN B12

    Vitamin B12 deficiency is thought to be one of the leading nutritional deficiencies in the world. An extensive 2004 study showed that deficiency is a major health concern in many parts of the world, including the North America, Central and South America, India, and certain areas in Africa. It is estimated that 40 percent of people may have low levels of vitamin B12.

    Vitamin B12 affects your mood, energy level, memory, nervous system, heart, skin, hair, digestion and more. It is a key nutrient regarding adrenal fatigue and multiple metabolic functions including enzyme production, DNA synthesis, and hormonal balance.

    Because of vitamin B12's extensive roles within the body, a vitamin deficiency can show up in many different symptoms, such as chronic fatigue, mood disorders such as depression, chronic stress, and low energy.

    SOURCES OF VITAMIN B12

    The only organisms to produce vitamin B12 are certain bacteria and archaea. Some of these bacteria are found in the soil around the grasses that ruminants eat. They are taken into the animal, proliferate, form part of their gut flora, and continue to produce vitamin B12.

    Products of animal origin such as beef (especially liver), chicken, pork, eggs, dairy, clams, and fish constitute the primary food source of vitamin B12. Older individuals and vegans are advised to use vitamin B12 fortified foods and supplements to meet their needs.

    vitamin B12 salmon Salmon is a good source of Vitamin B12

    Commercially, Vitamin B12 is prepared by bacterial fermentation. Fermentation by a variety of microorganisms yields a mixture of methylcobalamin, hydroxocobalamin, and adenosylcobalamin. Since multiple species of propionibacterium produce no exotoxins or endotoxins and have been granted GRAS status (generally regarded as safe) by the United States Food and Drug Administration, they are the preferred bacterial fermentation organisms for vitamin B12 production.

    Methylcobalamin and 5-deoxyadenosylcobalamin are the forms of vitamin B12 used in the human body (called coenzyme forms). The form of cobalamin used in many some nutritional supplements and fortified foods, cyanocobalamin, is readily converted to 5-deoxyadenosylcobalamin and methylcobalamin in the body.

    Hydroxocobalamin is the direct precursor of methylcobalamin and 5-deoxyadenosylcobalamin. In mammals, cobalamin is a cofactor for only two enzymes, methionine synthase (MS) and L-methylmalonyl-coenzyme A mutase (MUT).

    Unlike most other vitamins, B12 is stored in substantial amounts, mainly in the liver, until it is needed by the body. If a person stops consuming the vitamin, the body’s stores of this vitamin usually take about 3 to 5 years to exhaust. Vitamin B12 is primarily stored in the liver as 5-deoxyadenosylcobalamin, but is easily converted to methylcobalamin.

    ABSORPTION OF VITAMIN B12

    Vitamin B12, bound to protein in food, is released by the activity of hydrochloric acid and gastric protease in the stomach. Intestinal absorption of vitamin B12 requires successively three different protein molecules: Haptocorrin, Intrinsic Factor and Transcobalamin II. If there are deficiencies in any of these factors absorption of Vitamin B12 can be seriously decreased.

    When vitamin B12 is added to fortified foods and dietary supplements, it is already in free form and, thus, does not require the separation from food protein step. Free vitamin B12 then combines with intrinsic factor, a glycoprotein secreted by the stomach’s parietal cells, and the resulting complex undergoes absorption within the distal ileum by receptor-mediated endocytosis.

    Approximately 56% of a 1 mcg oral dose of vitamin B12 is absorbed, but absorption decreases drastically when the capacity of intrinsic factor is exceeded (at 1–2 mcg of vitamin B12).

    Vitamin B12 – 5 mg methylcobalamin sublingual lozenge Vitamin B12 – 5 mg Methylcobalamin sublingual lozenge.

    VITAMIN B12 DEFICIENCY

    Vitamin B12 deficiency can be difficult to detect, especially since the symptoms of a vitamin B12 deficiency can be similar to many common symptoms, such as feeling tired or unfocused, experienced by people for a variety of reasons.

    Vitamin B12 deficiency is commonly associated with chronic stomach inflammation, which may contribute to an autoimmune vitamin B12 malabsorption syndrome called pernicious anemia and to a food-bound vitamin B12 malabsorption syndrome. Poor absorption of vitamin may be related to coeliac disease. Impairment of vitamin B12 absorption can cause megaloblastic anemia and neurologic disorders in deficient subjects. In some cases, permanent damage can be caused to the body when B12 amounts are deficient.

    It is noteworthy that normal function of the digestive system required for food-bound vitamin B12 absorption is commonly impaired in individuals over 60 years of age, placing them at risk for vitamin B12 deficiency.

    A diagnosis of vitamin B12 deficiency is typically based on the measurement of serum vitamin B12 levels within the blood. However, studies show that about 50 percent of patients with diseases related to vitamin B12 deficiency have normal B12 levels when tested. This can cause individuals to ignore taking in adequate levels of vitamin B12 with potential serious consequences.

    FUNCTIONS AND ISSUES ASSOCIATED WITH VITAMIN B12 STATUS IN THE BODY

    • Vitamin B12 or cobalamin plays essential roles in folate metabolism and in the synthesis of the citric acid cycle intermediate, succinyl-CoA.

     

    • Vitamin B12 deficiency is commonly associated with chronic stomach inflammation, which may contribute to an autoimmune vitamin B12 malabsorption syndrome called pernicious anemia and to a food-bound vitamin B12 malabsorption syndrome. Impairment of vitamin B12 absorption can cause megaloblastic anemia and neurologic disorders in deficient subjects.

     

    • Normal function of the digestive system required for food-bound vitamin B12 absorption is commonly impaired in individuals over 60 years of age, placing them at risk for vitamin B12 deficiency.

     

    • Vitamin B12 and folate are important for homocysteine metabolism. Elevated homocysteine levels in blood are a risk factor for cardiovascular disease (CVD). B vitamin supplementation has been proven effective to control homocysteine levels.

     

    • The preservation of DNA integrity is dependent on folate and vitamin B12 availability. Poor vitamin B12 status has been linked to increased risk of breast cancer in some, but not all, observational studies.

     

    • Low maternal vitamin B12 status has been associated with an increased risk of neural tube defects (NTD), but it is not known whether vitamin B12 supplementation could help reduce the risk of NTD.

     

    • Vitamin B12 is essential for the preservation of the myelin sheath around neurons and for the synthesis of neurotransmitters. A severe vitamin B12 deficiency may damage nerves, causing tingling or loss of sensation in the hands and feet, muscle weakness, loss of reflexes, difficulty walking, confusion, and dementia.

     

    • While hyperhomocysteinemia may increase the risk of cognitive impairment, it is not clear whether vitamin B12 deficiency contributes to the risk of dementia in the elderly. Although B-vitamin supplementation lowers homocysteine levels in older subjects, the long-term benefit is not yet known.

     

    • Both depression and osteoporosis have been linked to diminished vitamin B12 status and high homocysteine levels.

     

    • The long-term use of certain medications, such as inhibitors of stomach acid secretion, can adversely affect vitamin B12 absorption.

     

    • Vitamin B12 is required for proper red blood cell formation, neurological function, and DNA synthesis.

     

    MORE DETAILS ASSOCIATED WITH VITAMIN B12 STATUS IN THE BODY

    1. Vitamin B12 is required for proper red blood cell formation, neurological function, and DNA synthesis. Vitamin B12 as methylcobalamin functions as a cofactor for methionine synthase. Methionine synthase (MS) catalyzes the conversion of homocysteine to methionine. Methionine along with ATP is required for the formation of S-adenosylmethionine (SAMe), a universal methyl donor for almost 100 different substrates, including DNA, RNA, hormones, proteins, and lipids.
    2. Vitamin B12 as 5-deoxyadenosylcobalamin functions as a cofactor along with L-methylmalonyl-CoA mutase (MUT) to convert L-methylmalonyl-CoA to succinyl-CoA in the degradation of propionate, an essential biochemical reaction in fat and protein metabolism. Succinyl-CoA is also required for hemoglobin synthesis.
    Metabolic Pathway

     

    3. Vitamin B12, bound to protein in food, is released by the activity of hydrochloric acid and gastric protease in the stomach. When synthetic vitamin B12 is added to fortified foods and dietary supplements, it is already in free form and, thus, does not require this separation step. Free vitamin B12 then combines with intrinsic factor, a glycoprotein secreted by the stomach’s parietal cells, and the resulting complex undergoes absorption within the distal ileum by receptor-mediated endocytosis. Approximately 56% of a 1 mcg oral dose of vitamin B12 is absorbed, but absorption decreases drastically when the capacity of intrinsic factor is exceeded (at 1–2 mcg of vitamin B12).

    4. Pernicious anemia is an autoimmune disease that affects the gastric mucosa and results in gastric atrophy. This leads to the destruction of parietal cells, achlorhydria, and failure to produce intrinsic factor, resulting in vitamin B12 malabsorption. If pernicious anemia is left untreated, it causes vitamin B12 deficiency, leading to megaloblastic anemia and neurological disorders, even in the presence of adequate dietary intake of vitamin B12.

    5. Vitamin B12 status is typically assessed via serum or plasma vitamin B12 levels. Values below approximately 170–250 pg/mL (120–180 picomol/L) for adults indicate a vitamin B12 deficiency. However, evidence suggests that serum vitamin B12 concentrations might not accurately reflect intracellular concentrations. An elevated serum homocysteine level (values >13 micromol/L) might also suggest a vitamin B12 deficiency. However, this indicator has poor specificity because it is influenced by other factors, such as low vitamin B6 or folate levels. Elevated methylmalonic acid levels (values >0.4 micromol/L) might be a more reliable indicator of vitamin B12 status because they indicate a metabolic change that is highly specific to vitamin B12 deficiency.

    6. Vitamin B12 deficiency is characterized by megaloblastic anemia, fatigue, weakness, constipation, loss of appetite, and weight loss. Neurological changes, such as numbness and tingling in the hands and feet, can also occur . Additional symptoms of vitamin B12 deficiency include difficulty maintaining balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue. The neurological symptoms of vitamin B12 deficiency can occur without anemia, so early diagnosis and intervention is important to avoid irreversible damage. During infancy, signs of a vitamin B12 deficiency include failure to thrive, movement disorders, developmental delays, and megaloblastic anemia. Many of these symptoms are general and can result from a variety of medical conditions other than vitamin B12 deficiency.

    7. Typically, vitamin B12 deficiency is treated with vitamin B12 injections, since this method bypasses potential barriers to absorption. However, high doses of oral vitamin B12 can also be effective. The authors of a review of randomized controlled trials comparing oral with intramuscular vitamin B12 concluded that 2,000 mcg (I like 5,000 mcg) of oral vitamin B12 daily, followed by a decreased daily dose of 1,000 mcg and then 1,000 mcg weekly and finally, monthly might be as effective as intramuscular administration. Overall, an individual patient’s ability to absorb vitamin B12 is the most important factor in determining whether vitamin B12 should be administered orally or via injection. In most countries, the practice of using intramuscular vitamin B12 to treat vitamin B12 deficiency has remained unchanged.

    8. Large amounts of folate can mask the damaging effects of vitamin B12 deficiency by correcting the megaloblastic anemia caused by vitamin B12 deficiency without correcting the neurological damage that also occurs. Moreover, preliminary evidence suggests that high serum folate levels might not only mask vitamin B12 deficiency, but could also exacerbate the anemia and worsen the cognitive symptoms associated with vitamin B12 deficiency. Permanent nerve damage can occur if vitamin B12 deficiency is not treated. For these reasons, folate intake from fortified food and supplements should not exceed 1,000 mcg daily in healthy adults.

    Groups at Risk of Vitamin B12 Deficiency

    The main causes of vitamin B12 deficiency include vitamin B12 malabsorption from food, pernicious anemia, postsurgical malabsorption, and dietary deficiency. However, in many cases, the cause of vitamin B12 deficiency is unknown. The following groups are among those most likely to be vitamin B12 deficient.

    Older adults: Atrophic gastritis, a condition affecting 10%–30% of older adults, decreases secretion of hydrochloric acid in the stomach, resulting in decreased absorption of vitamin B12. Decreased hydrochloric acid levels might also increase the growth of normal intestinal bacteria that use vitamin B12, further reducing the amount of vitamin B12 available to the bodY.

    Individuals with atrophic gastritis are unable to absorb the vitamin B12 that is naturally present in food. Most, however, can absorb the synthetic vitamin B12 added to fortified foods and dietary supplements. As a result, the IOM recommends that adults older than 50 years obtain most of their vitamin B12 from vitamin supplements or fortified foods. However, some elderly patients with atrophic gastritis require doses much higher than the RDA to avoid subclinical deficiency.

    Individuals with pernicious anemia: Pernicious anemia, a condition that affects 1%–2% of older adults, is characterized by a lack of intrinsic factor. Individuals with pernicious anemia cannot properly absorb vitamin B12 in the gastrointestinal tract. Pernicious anemia is usually treated with intramuscular vitamin B12. However, approximately 1% of oral vitamin B12 can be absorbed passively in the absence of intrinsic factor, suggesting that high oral doses of vitamin B12 might also be an effective treatment.

    Individuals with gastrointestinal disorders: Individuals with stomach and small intestine disorders, such as celiac disease and Crohn’s disease, may be unable to absorb enough vitamin B12 from food to maintain healthy body stores. Subtly reduced cognitive function resulting from early vitamin B12 deficiency might be the only initial symptom of these intestinal disorders, followed by megaloblastic anemia and dementia.

    Individuals who have had gastrointestinal surgery: Surgical procedures in the gastrointestinal tract, such as weight loss surgery or surgery to remove all or part of the stomach, often result in a loss of cells that secrete hydrochloric acid and intrinsic factor. This reduces the amount of vitamin B12, particularly food-bound vitamin B12, that the body releases and absorbs. Surgical removal of the distal ileum also can result in the inability to absorb vitamin B12. Individuals undergoing these surgical procedures should be monitored preoperatively and postoperatively for several nutrient deficiencies, including vitamin B12 deficiency.

    Vegetarians: Strict vegetarians and vegans are at greater risk than lacto-ovo vegetarians and non-vegetarians of developing vitamin B12 deficiency because natural food sources of vitamin B12 are limited to animal foods. Fortified breakfast cereals and fortified nutritional yeasts are some of the only sources of vitamin B12 from plants and can be used as dietary sources of vitamin B12 for strict vegetarians and vegans. Fortified foods vary in formulation, so it is important to read the Nutrition Facts labels on food products to determine the types and amounts of added nutrients they contain.

    Pregnant and lactating women who follow strict vegetarian diets and their infants: Vitamin B12 crosses the placenta during pregnancy and is present in breast milk. Exclusively breastfed infants of women who consume no animal products may have very limited reserves of vitamin B12 and can develop vitamin B12 deficiency within months of birth. Undetected and untreated vitamin B12 deficiency in infants can result in severe and permanent neurological damage.

    The American Dietetic Association recommends supplemental vitamin B12 for vegans and lacto-ovo vegetarians during both pregnancy and lactation to ensure that enough vitamin B12 is transferred to the fetus and infant. Pregnant and lactating women who follow strict vegetarian or vegan diets should consult with a pediatrician regarding vitamin B12 supplements for their infants and children.

    Health Risks from Excessive Vitamin B12

    The IOM did not establish a UL for vitamin B12 because of its low potential for toxicity. In Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline, the IOM states that “no adverse effects have been associated with excess vitamin B12 intake from food and supplements in healthy individuals”.

    Findings from intervention trials support these conclusions. In the NORVIT and HOPE 2 trials, vitamin B12 supplementation (in combination with folic acid and vitamin B6) did not cause any serious adverse events when administered at doses of 0.4 mg for 40 months (NORVIT trial) and 1.0 mg for 5 years (HOPE 2 trial).

    Interactions with Medications

    Vitamin B12 has the potential to interact with certain medications. In addition, several types of medications might adversely affect vitamin B12 levels. A few examples are provided below. Individuals taking these and other medications on a regular basis should discuss their vitamin B12 status with their healthcare providers.

    Chloramphenicol: Chloramphenicol (Chloromycetin®) is a bacteriostatic antibiotic. Limited evidence from case reports indicates that chloramphenicol can interfere with the red blood cell response to supplemental vitamin B12 in some patients.

    Proton pump inhibitors: Proton pump inhibitors, such as omeprazole (Prilosec®) and lansoprazole (Prevacid®), are used to treat gastroesophageal reflux disease and peptic ulcer disease. These drugs can interfere with vitamin B12 absorption from food by slowing the release of gastric acid into the stomach. However, the evidence is conflicting on whether proton pump inhibitor use affects vitamin B12 status. As a precaution, healthcare providers should monitor vitamin B12 status in patients taking proton pump inhibitors for prolonged periods.

    H2 receptor antagonists: Histamine H2 receptor antagonists, used to treat peptic ulcer disease, include cimetidine (Tagamet®), famotidine (Pepcid®), and ranitidine (Zantac®). These medications can interfere with the absorption of vitamin B12 from food by slowing the release of hydrochloric acid into the stomach. Although H2 receptor antagonists have the potential to cause vitamin B12 deficiency, no evidence indicates that they promote vitamin B12 deficiency, even after long-term use. Clinically significant effects may be more likely in patients with inadequate vitamin B12 stores, especially those using H2 receptor antagonists continuously for more than 2 years.

    Metformin: Metformin, a hypoglycemic agent used to treat diabetes, might reduce the absorption of vitamin B12, possibly through alterations in intestinal mobility, increased bacterial overgrowth, or alterations in the calcium-dependent uptake by ileal cells of the vitamin B12-intrinsic factor complex. Small studies and case reports suggest that 10%–30% of patients who take metformin have reduced vitamin B12 absorption. In a randomized, placebo controlled trial in patients with type 2 diabetes, metformin treatment for 4.3 years significantly decreased vitamin B12 levels by 19% and raised the risk of vitamin B12 deficiency by 7.2% compared with placebo. Some studies suggest that supplemental calcium might help improve the vitamin B12 malabsorption caused by metformin, but not all researchers agree.

    REFERENCES

    FROM: https://academic.oup.com/ajcn/article/71/2/514/4729184
    Plasma vitamin B-12 concentrations relate to intake source in the Framingham Offspring Study

    The American Journal of Clinical Nutrition, Volume 71, Issue 2, 1 February 2000, Pages 514–522, https://doi.org/10.1093/ajcn/71.2.514

    ABSTRACT

    Background: Low vitamin B-12 status is prevalent among the elderly, but few studies have examined the association between vitamin B-12 status and intake.
    Objective: We hypothesized that vitamin B-12 concentrations vary according to intake source.
    Design: Plasma concentrations and dietary intakes were assessed cross-sectionally for 2999 subjects in the Framingham Offspring Study. The prevalence of vitamin B-12 concentrations <148, 185, and 258 pmol/L was examined by age group (26–49, 50–64, and 65–83 y), supplement use, and the following food intake sources: fortified breakfast cereal, dairy products, and meat.
    Results: Thirty-nine percent of subjects had plasma vitamin B-12 concentrations <258 pmol/L, 17% had concentrations <185 pmol/L, and 9% had concentrations <148 pmol/L, with little difference between age groups. Supplement users were significantly less likely than non-supplement-users to have concentrations <185 pmol/L (8% compared with 20%, respectively). Among non-supplement-users, there were significant differences between those who consumed fortified cereal >4 times/wk (12%) and those who consumed no fortified cereal (23%) and between those in the highest and those in the lowest tertile of dairy intake (13% compared with 24%, respectively), but no significant differences by meat tertile. Regression of plasma vitamin B-12 on log of intake, by source, yielded significant slopes for each contributor adjusted for the others. For the total group, b = 40.6 for vitamin B-12 from vitamin supplements. Among non-supplement-users, b = 56.4 for dairy products, 35.2 for cereal, and 16.7 for meat. Only the meat slope differed significantly from the others.
    Conclusions: In contrast with previous reports, plasma vitamin B-12 concentrations were associated with vitamin B-12 intake. Use of supplements, fortified cereal, and milk appears to protect against lower concentrations. Further research is needed to investigate possible differences in bioavailability.

     

    INTERNET REFERENCES

  • METHYLATION CYCLE, GENETICS, B VITAMINS

    Dr. Hank Liers, PhD geneticsI previously published "Homocysteine Genetics – Coenzyme B Vitamins" in which I considered in-depth how homocysteine (an intermediate chemical in the Methylation Cycle) is formed from methionine, how genetics affects the metabolic pathways, and how B vitamins are used in metabolic pathways. I also wrote "Folate Ingredients – Folinic Acid & 5-MTHF" which discussed how coenzyme folate vitamins are far superior to the synthetic folic acid form. In today's article, I take a broader view of the topic that encompasses the Methylation Cycle, genetics, and B vitamins.

    THE METHYLATION CYCLE

    The Methylation Cycle is considered to be one of the most important metabolic pathways in the human body. Its most important function is to provide methyl groups via SAM (S-adenosyl methionine) to hundreds of different body substrates. Methylation is continually occurring in the body, transforming many millions of molecules throughout the body every second. Molecules receive methyl groups, then separate and recombine continuously, transforming and reforming constantly in the ongoing process of life!

    As a reminder of the pathways involved in the Methylation Cycle, the following figure provides a flow chart showing the details.

    Methylation Cycle

    Figure 1. Metabolic Pathways in Methylation Cycle

    A key purpose of this cycle is to provide methyl groups (CH3) needed by a broad range of of body functions (over 200 different functions). Examples include:

    1. Influences the genetic expression that parents give their children and helps guide the development of the embryo.
    2. Is needed by the nervous system to produce neurotransmitters and maintain the nerves.
    3. Mobilizes fats and cholesterol so they do not accumulate where they are harmful, such as the arteries and liver.
    4. Regulates hormones, including, estrogen, adrenaline, and melatonin.
    5. Detoxifies harmful chemicals and histamine a prime substance involved in inflammation.
    6. Helps repair damaged proteins in the cells so they can function properly.
    7. Protects the DNA in the genome (genetic code) to reduce the chances of mutation.
    8. Creates antioxidants used in the antioxidant defense system.

    DESCRIPTION OF PATHWAYS WITHIN THE METHYLATION CYCLE

    The overall flow of the Methylation Cycle begins with dietary methionine (an essential amino acid) which combines with ATP (adenosine triphosphate - body energy) to form SAM (S-adenosyl methionine) – the common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. When SAM transfers a methyl group to a body chemical the residue from this reaction leads to the production of homocysteine.

    Homocysteine can be converted in the transsulfuration pathway that requires coenzyme vitamin B6 to produce cysteine, glutathione, taurine, and sulfates. These sulfur containing substances provide important antioxidant protection and detoxification functions in the body.

    Homocysteine can be converted back to methionine through the betaine (trimethyl glycine) pathway which requires zinc and magnesium. This pathway also requires dietary betaine or choline which the body can convert into betaine.

    Also, homocysteine can be converted back to methionine via the remethylation pathway which requires 5-MTHF, coenzyme vitamin B2 and methylcobalamin (B12).

    GENETICS

    It is important to understand that each of the pathways described above are able to be executed only in the presence of enzymes (shown in blue boxes in the diagram) created by specific genes in your genetic code. For example, Betaine-Homocysteine S-Methyltransferase (BHMT) is the enzyme required in the betaine pathway, Cystathione Beta Synthase (CBS) is the enzyme required in the transsulfuration pathway, and Methylenetetrahydrofolate Reductase (MTHFR) and Methionine Synthase (MS) are enzymes required in the remethylation pathway.

    Assuming that you have perfect genetics (no mutations, SNPs, free radical damage, insertions/deletions, etc.), the proper functioning of these pathways are still subjected to the fact that the required vitamins and minerals (vitamin B6, vitamin B2, Folate, vitamin B12, zinc, magnesium, and betaine) need to be provided by your diet or from supplements for the body to function correctly.

    In addition, exposure to high levels of toxins from your environment and high levels of stress require that the nutritional needs will be even higher for the pathways to work properly. For example, exposure to high levels of toxins requires that the transsulfuration pathway be more active possibly reducing the amount of available methionine to support necessary methyl transfer reactions.

    For these reasons alone the consensus of knowledgeable practitioners is that you should be eating an organic whole foods diet, taking appropriate nutritional supplements, avoiding and eliminating toxins from food, water, and air (living in a clean environment), and avoiding an unduly stressful life. All of these actions fall into the category of Epigenetics which you generally have control over!! Doing these things alone could significantly balance the functioning of your Methylation Cycle and improve your health.

    Unfortunately, few people have perfect genetics which often causes the various pathways in the Methylation Cycle to become imbalanced and unable to correct the dysregulation imposed upon the body. For example, the enzyme MTHFR can have heterozygous (single chromosome) genetic variations in up to 50% of certain populations and homozygous genetic variations (both chromosomes) in 10% or more of certain populations.

    Some disorders that researchers have associated with MTHFR genetic variations include:

    • Alzheimer’s disease
    • Asthma
    • Atherosclerosis
    • Autism
    • Bipolar disorder
    • Bladder issues
    • Blood clots
    • Breast problems
    • Chemical sensitivity
    • Chronic fatigue syndrome
    • Down syndrome
    • Epilepsy
    • Fibromyalgia
    • Gastric problems
    • Glaucoma
    • Heart murmurs
    • High blood pressure
    • Irritable bowel syndrome
    • Leukemia
    • Male infertility
    • Methotrexate toxicity
    • Migraines with aura
    • Multiple sclerosis
    • Myocardial infarction
    • Nitrous oxide toxicity
    • Parkinson’s disease
    • Pulmonary embolisms
    • Schizophrenia
    • Stroke
    • Thyroid issues
    • Unexplained neurologic disease
    • Vascular dementia

    This extensive list is highly significant and tells us that it is very important to have  genetic testing done for the genes/enzymes in the Methylation Cycle pathway. I prefer the BodySync genetic test which evaluates the key Methylation Cycle genes plus many other important genes in a single test.

    B VITAMINS AND MINERALS

    We are strong believers that everyone should start their nutritional program by eating a balanced, organic, whole foods diet. We have been doing this ourselves for the past 30 years. Unfortunately, only a small percentage of people follow this advice and in most cases this leads to poor nutritional status that does not adequately support the body's needs. This is especially true with respect to obtaining the nutrients needed to support the Methylation Cycle.

    Nine of our family members and associates have taken the BodySync genetic test which evaluates the condition of 45 different enzymes including CBS, MTHFR (2 variations), MTR (related to B12 and 5-MTHF as they relate to methionine synthase - MS), and MTRR (related to maintaining B12 levels needed by the MTR enzyme). In every case the results showed at least 2 and up to 4 enzymes had genetic variations. These results indicate that the nutritional requirements for folate as 5-MTHF, vitamin B12 as methylcobalamin, vitamin B6, vitamin B2, magnesium and zinc will likely be significantly greater than normal.

    Given the above information, it seems essential for good health to take nutritional supplements that provide the important nutrients. Below I will discuss various formulas that I have developed and refined over many years that are useful especially for the Methylation Cycle.

    Please note that Health Products Distributors, Inc.  (HPDI) is the preferred supplier of nutritional supplements by the BodySync genetic testing company.

    MULTIVITAMINS

    When looking at the total needs the body has for nutrients that the body does not produce, including fat soluble vitamins (A, D (some), E, K1 and K2), vitamin C, B vitamins (B1, B2, B3, B5, B6, folate, B12, biotin, choline, and inositol), minerals (Ca, Mg, Zn, Se, Cu, Mn, Cr, Mo, K, boron, and vanadium), and betaine it only seems wise to include as a top priority a Multivitamin that includes all of these in what I term therapeutic amounts (carefully selected after evaluating thousands of research studies carried out over many years.)

    In this context, it is important to recognize that every enzymatic reaction in the body requires mineral cofactors in order to carry out its function. A good multivitamin provides many of these required minerals.

    Additionally, the multivitamin should contain ingredient forms that research has confirmed to be the most absorbable and usable by the body. These include coenzyme B vitamins, Krebs cycle (citrate, alpha-ketoglutarate, succinate, fumarate, & malate) minerals, and amino acid chelates.

    In the context of supporting the Methylation Cycle we are looking for specific forms and amounts of B vitamins that can adequately provide the body's needs. The means that there should be coenzyme folate as 5-MTHF of at least 400 mcg, coenzyme vitamin B-12 as methylcobalamin of at least 200 mcg, Vitamin B6 (including significant amounts of pyridoxal 5' phosphate) of at least 40 mg, and Vitamin B2 (including significant amounts of riboflavin 5' phosphate) of at least 25 mg. In addition, magnesium (100 mg) and zinc (at least 20 mg) should be provided.

    Please note that the body's requirements for magnesium is generally accepted by nutritional experts to be higher than 400 mg daily (and as high as 1,000 mg daily). For this reason we generally recommend that a person take supplemental magnesium (such as HPDI's MYO-MAG) at levels over 400 mg daily.

    The two multivitamin formulas Health Products Distributors provides for adults that meet these requirements (and more) are the Hank & Brian's Mighty Multi-Vite and Multi Two (in both capsule and tablet forms). Click on the bottles below for technical details.

    Hank & Brian's Mighty Multi-Vite multivitamin methylation cycle

    Multi Two Caps or Tablets methylation cycle

    B COMPLEX

    In situations where significant genetic variations are present it may be wise to add a B COMPLEX supplement to the MULTIVITAMIN to provide even larger amounts of the needed B vitamins. HPDI provides a B-Complex-50 product that includes significant amounts of coenzyme forms and contains 50 mg of Vitamin B1, 50 mg of Vitamin B2, 100 mg of Vitamin B3, 50 mg of Vitamin B6, 500 mcg of coenzyme folate (both folinic acid and 5-MTHF), 100 mcg of B12 (both methylcobalamin and hydroxocobalmin), 50 mg of Vitamin B5 (pantothenic acid), 500 mg of Biotin, 50 mg of choline, and 50 mg of inositol. Click on the bottle below for technical details.

    B-Complex-50 full spectrum B vitamins with coenzyme forms methylation cycle

    FOLATE AS 5-MTHF

    In situations where an inadequate diet is present and genetic testing indicates an MTHFR variation (especially a homozygous variation) Health Products Distributors provides a 5-MTHF folate supplement that easily absorbs into the body and can be directly used in combination with Vitamin B12 to convert homocysteine to methionine. Click on the bottle below for technical details.

    5-MTHF 1 mg in veggie cap methylation cycle 5-MTHF 1 mg in veggie cap

    B-12 as METHYLCOBALAMIN

    It is often the case for older patients and vegetarians that Vitamin B12 is deficient. In these cases it is wise to supplement with a significant amount of methylcobalamin to ensure that the Methylation Cycle has sufficient to effectively convert homocysteine into methionine. Health Products Distributors Vitamin B12 contains 5 mg of methylcobalamin in sublingual lozenge form that supports excellent absorption even if swallowed and absorbed by diffusion. Click on the bottle below for technical details.

    Vitamin B-12 5 mg methylcobalamin sublingual lozenge methylation cycle Vitamin B-12 – 5 mg Methylcobalamin sublingual lozenge.

    MINERALS

    Magnesium and zinc are two important minerals used in the betaine pathway of the Methylation Cycle in which homocysteine is converted back to methionine.

    In the body magnesium is involved in more than 400 essential metabolic reactions and is required by the adenosine triphosphate (ATP)-synthesizing protein in mitochondria. ATP, the molecule that provides energy for almost all metabolic processes, exists primarily as a complex with magnesium (MgATP). Therefore, it also is involved in converting methionine to SAM.

    Over 300 different enzymes depend on zinc for their ability to catalyze vital chemical reactions. Zinc-dependent enzymes can be found in all known classes of enzymes.

    Health Products Distributors provides 100 mg magnesium/vcap in its MYO-MAG supplement which is especially important in increasing ATP in the Krebs Cycle. This product also contains vitamin B1, vitamin B2, and vitamin B6 with substantial amounts of coenzyme forms and manganese. Click on the bottle below for technical details.

    MYO-MAG with 100 mg magnesium per serving key B vitamins methylation cycle MYO-MAG with 100 mg magnesium per serving and key B vitamins.

    Health Products Distributors provides 25 mg zinc/serving in its Double Zinc Plus supplement. This formula provides zinc in the picolinate and citrate forms as well as 3 mg of P5P (coenzyme B6). Click on the bottle below for technical details.

    Double Zinc Plus supplement with P5P and 25 mg zinc methylation cycle Double Zinc Plus supplement with P5P and 25 mg zinc

    SUMMARY

    The Methylation Cycle is recognized as one of the most important metabolic pathways in the human body. When not properly supported by key B vitamins and minerals, the Methylation Cycle can become severely imbalanced which can lead to a very wide range of poor health conditions. Furthermore, genetic variations in the genes that produce important enzymes allowing the Methylation Cycle to function correctly lead to even further imbalances and greater possibility for conditions of poor health.

    In this article, I have provided insight into how the Methylation Cycle works and how it can be significantly supported by lifestyle changes regarding diet and environment (Epigenetics) and by specific B vitamins and mineral supplements that I have developed over many years. In addition, we have shown that knowledge gained from genetic testing can further provide a critical understanding of your specific needs so that your health can be optimized.

    RELATED HPDI BLOG ARTICLES

    GENETICS, EPIGENETICS & HUMAN BIOLOGY

    Homocysteine Genetics – Coenzyme B Vitamins

     

  • HOMOCYSTEINE GENETICS – COENZYME B VITAMINS

    Dr. Hank Liers, PhD homocysteine coenzyme B vitaminsWe previously published an article titled FOLATE INGREDIENTS – FOLINIC ACID & 5-MTHF in which we discuss how coenzyme folate vitamins are far superior to the synthetic folic acid form. In today's article, I take a more in-depth look at how homocysteine is formed from methionine, how genetics affects the metabolic pathways, and how B vitamins are used in metabolic pathways.

    One way to look at the metabolic pathways of methionine (an essential amino acid) is that it provides a way for the body to convert this sulfur containing amino acid either to cysteine and its key by-products glutathione, taurine, and sulfates or allows remethylation back to methionine to occur using either the Folate Cycle or the Trimethyl glycine (betaine) pathways.

    Figure 1 shows these metabolic pathways including the vitamins required at each step including vitamin B6 (as P-5-P), methylcobalamin, and 5-methyltetrahydrofolate (5-MTHF). In addition, it shows the key enzymes produced by the body at each step. These enzymes include CBS (cystathione beta synthase), BHMT (betaine homocysteine methyltransferase), MS (methionine synthase), and MTHFR (methylene tetrahydrofolate reductase).

    homocysteine metabolism diagram Figure 1. Metabolic Pathways in Methionine and Homocysteine Metabolism

    HEALTH ISSUES ASSOCIATED WITH HIGH HOMOCYSTEINE LEVELS

    It is highly important that the various metabolic pathways function correctly to keep homocysteine at healthy levels (6–8 µmol/L). Unfortunately, high levels of homocysteine in the body (10–20 µmol/L) are a factor in a wide range of health issues, including:

    • Greater risk for heart problems, including coronary artery disease, heart attacks, stroke, high blood pressure, congestive heart failure, and abnormal cholesterol levels. This is due to increased inflammation, sometimes due to blood clotting spontaneously, and because of blockages of the major arteries.
    • Mental abnormalities such as depression, anxiety, bipolar disorder, and other mental problems are more common among people with high homocysteine
    • Migraines and headaches in a significant percentage of the population
    • In those who suffer from high homocysteine due to having nutritional deficiencies anemia, aches and pains, hearing loss, age-related macular degeneration (ARMD), slowed development, and birth defects might also be possible
    • Greater risk for dementia, Alzheimer’s disease, brain atrophy, and other cognitive problems
    • In children, skeletal and developmental abnormalities including having a curved spine or protruding chest and rib cage. Some patients appear very tall and thin, and some might also have very long, thin “spider-like” toes and fingers.
    • Behavioral problems, including ADHD, autism and other learning disabilities

    ROLE OF GENETICS IN HOMOCYSTEINE METABOLISM

    Ten or more years ago, questions of how genetics enters into homocysteine metabolism were unlikely to be asked. However, in recent years DNA testing has advanced and is now available to everyone (for example, see my article about Bodysync's genetic test, GET STARTED – NUTRIGENOMIC TESTING.

    You may have heard a great deal about MTHFR (methylene tetrahydrofolate reductase). This gene is involved in folate metabolism and has a central role in methylation processes like repair of and building new DNA in dividing cells.

    In the remethylation pathway for conversion of homocysteine to methionine, MTHFR plays a key role in converting folate into 5-MTHF which is needed along with B12 as methylcobalamin in order for the conversion to take place. Genetic variations in MTHFR have been studied in depth. Of the many variations studies the most significant ones appear to be variations of C677C such as C677T (referred to as heterozygous) or T677T (referred to as homozygous). The heterozygous variant appears in about 30–50% of the population and causes somewhat less efficiency in the conversion of folic acid to 5-MTHF. However, the homozygous variation occurs in about 10% of the population and can have serious effects due to converting little homocysteine back to methionine.

    Another variation in MTHFR is called A1298A. These variations are A1298C and C1298C and will have similar effects to the C677C variations. It was interesting to me when I recently analyzed my Bodysync genetic test results showing I carry the variation A1298C (heterozygous), which indicates I may not be effectively converting homocysteine back to methionine.

    Additionally, my Bodysync genetic test results also indicate that I have heterozygous variations in the CBS enzyme shown in Figure 1, as well as heterozygous variations in MTR and MTRR enzymes, which are involved with B12 levels in the  remethylation pathway. These results indicate that I need to take higher levels of methylcobalamin and 5-MTHF.

    IMPORTANCE OF COENZYME FORMS AND PROPER AMOUNTS OF B VITAMINS

    Many of the B vitamins on the market today unfortunately are in synthetic form. The body can only use the natural coenzyme forms effectively. For example, the body needs vitamin B6 in the form of P-5-P (pyridoxal-5-phosphate), folate in the form of L-5-MTHF, and B12 in the form of methylcobalamin for proper metabolism of methionine. In some cases the body can use the synthetic forms of pyridoxine HCl, folic acid, and cyanocobalamin but pays a cost (e.g., in time and energy) by having to convert synthetic forms to coenzyme forms.

    Add to the prevalence of synthetic B vitamins, the fact that genetic deficiencies are more common than previously assumed, and it becomes clear that the coenzyme forms of B vitamins in the proper amounts are extremely important.

    Fortunately, I have always believed it best to include as many coenzyme forms as possible in the nutritional supplements I formulate (over the past 27 years). For example, all HPDI multivitamins include coenzymes of B1, B2, B6, B12, and folate (as 5-MTHF and folinic acid). This is uncommon in most multivitamin formulas on the market. For this reason our supplements are ideally suited to the prevention or resolution of most genetic problems regarding homocysteine.

    In addition, I have always chosen to include higher amounts than most multivitamins on the market. We also make available 5-MTHF one milligram (1 mg) capsules and methylcobalamin five milligram (5 mg) sublingual tablets. When genetic variations are in play as discussed above, then providing relatively higher amounts of coenzyme B vitamins that support important requirements in the body seems necessary.

    Interestingly, several other nutrients are involved in the pathways involving methionine and homocysteine. These include zinc, magnesium, and Vitamin B2. Our multivitamin formulas and magnesium formulas, especially Myo-Mag with its coenzyme B1, B2, and B6, are recommended to support these nutrient needs. Finally, it has been found that N-Acetyl-L-Cysteine (NAC) can significantly lower homocysteine (by up to 50%), most likely because its gives the body an excellent source of cysteine without have to use methionine.

    SUMMARY

    In this article, I have shown the value of the use of genetic testing and high-quality coenzyme B vitamins in resolving health issues associated with high values of homocysteine in the body.

     

    SOURCES & RESOURCES

     GET STARTED – NUTRIGENOMIC TESTING.

    FOLATE INGREDIENTS – FOLINIC ACID & 5-MTHF

    The Homocysteine Revolution by Kilmer S. McCully, MD

    "Role of hyperhomocysteinemia in endothelial dysfunction and atherothrombotic disease"
    (Cell Death and Differentiation 11, S56–S64)

    PRODUCTS

    5-MTHF
    (coenzyme folate)

    Methylcobalamin
    (vitamin B12)

    B-Complex-50

    HPDI Multivitamins

3 Item(s)