Posts filed under 'Vitamins & Minerals'
Even though dietary surveys suggest that many Americans do not consume recommended amounts of magnesium, symptoms of magnesium deficiency are rarely seen in the US. However, there is concern about the prevalence of sub-optimal magnesium stores in the body. For many people, dietary intake may not be high enough to promote an optimal magnesium status, which may be protective against disorders such as cardiovascular disease and immune dysfunction.
The health status of the digestive system and the kidneys significantly influence magnesium status. Magnesium is absorbed in the intestines and then transported through the blood to cells and tissues. Approximately one-third to one-half of dietary magnesium is absorbed into the body. Gastrointestinal disorders that impair absorption such as Crohn’s disease can limit the body’s ability to absorb magnesium. These disorders can deplete the body’s stores of magnesium and in extreme cases may result in magnesium deficiency. Chronic or excessive vomiting and diarrhea may also result in magnesium depletion.
Healthy kidneys are able to limit urinary excretion of magnesium to compensate for low dietary intake. However, excessive loss of magnesium in urine can be a side effect of some medications and can also occur in cases of poorly-controlled diabetes and alcohol abuse.
Early signs of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur. Severe magnesium deficiency can result in low levels of calcium in the blood (hypocalcemia). Magnesium deficiency is also associated with low levels of potassium in the blood (hypokalemia).
Many of these symptoms are general and can result from a variety of medical conditions other than magnesium deficiency. It is important to have a physician evaluate health complaints and problems so that appropriate care can be given.
July 6th, 2005
Magnesium is the fourth most abundant mineral in the body and is essential to good health. Approximately 50% of total body magnesium is found in bone. The other half is found predominantly inside cells of body tissues and organs. Only 1% of magnesium is found in blood, but the body works very hard to keep blood levels of magnesium constant.
Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis. There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes. Dietary magnesium is absorbed in the small intestines. Magnesium is excreted through the kidneys.
July 6th, 2005
What do you know about Chromium Picolinate?
Chromium Picolinate is sold over the counter as a nutritional supplement. Chromium works with insulin in assisting cells to take in glucose and release energy. When Chromium is lacking, the effectiveness of insulin is lessened and impaired tolerance to glucose. Deficiency is rare except in persons who must rely completely on intravenous fluids (hyperalimentation) for long term.
There had been scientific references that suggested that supplementing with Chromium Picolinate would enhance insulin utilization. That has not proven consistently true in current research.
Chromium can be measured in hair and blood. But laboratory methods to determine chromium levels are lacking. This is why a chromium requirement has not been determined. There is no Recommended Dietary Allowances (RDA) for Chromium. Toxicity of chromium is low according to the National Academy of Sciences. However since people have started to supplement with chromium picolinate, there have been several cases of toxicity which resulted in chronic renal failure and accumulation of chromium in tissues. Persons with behavior disorders are warned to avoid chromium supplements.
I’ve seen Chromium Picolinate advertised recently as a “metabolism boosting” diet supplement. Is there any merit to this claim?
Quite frankly, no. Initially there was some speculation that since Chromium is a component of the hormone insulin that additional Chromium would enhance insulin’s ability to break down glucose. Research has not supported this concept.
Is there any relationship between strenuous exercise, chromium and insulin resistance?
Would you consider a chromium supplement with reduction in sugar consumption?
What are natural sources of chromium?
Does magnesium also factor into this?
I exercise treadmill/Stairmaster 6/7 days a week and blood sugar recently was up to 160 - 190 ranges. Lower carbohydrate/ sugar has reduced this level.
Exercise probably decreases insulin resistance if the exercise reduces body fat which is one cause of increased insulin resistance. Your exercise program sounds good, but you should talk to an exercise physiologist about adding some weight training exercises.
Chromium is involved in the production of insulin and the release of glucose’s energy from cells. Taking a chromium supplement will not increase the production of insulin unless your diet is deficient in chromium. Your body releases insulin from your pancreas in response to an elevated blood sugar level. Recent research does not support taking a chromium supplement for persons with diabetes or pre-diabetic insulin resistance.
Food sources of chromium are meats, unrefined foods (whole grains, fruits and vegetables), fats and vegetable oils.
Sugar reduction is always an improvement to a healthy diet and reducing an elevated blood glucose. You may want to talk to a Registered Dietitian about a diabetic meal plan as a blood sugar of 160 to 180 is more than a slight elevation. Fasting blood glucose should be 70 to 110 mg/dl. It is normal for blood glucose to double within 2 hours after a meal. When was your blood glucose taken? After a meal or fasting in the morning?
Magnesium is involved with calcium and phosphorus in depositing these minerals in bones and teeth, the transmission of nerve impulses, building of protein structures, enzymes and muscle contraction. Based on today’s knowledge, magnesium is not involved in blood glucose levels or insulin production.
July 6th, 2005
I read where chromium picolinate is recommended for people with hypoglycemia. Can a person vary on the amount taken daily? (i.e. take more when in a bad mood)
Also, is there a certain amount of sugar able to be taken that won’t effect one’s emotional state? Also, is there a recommended diet?
First of all, sweets do affect a person’s mood, but with varying results from different amounts. Secondly, chromium as a mineral functions as a glucose tolerance factor, but the question is, what amount is appropriate as a supplement and can it be toxic?
It is not recommended to use chromium picolinate to control blood sugar levels. There is no proof that chromium supplements can help treat or prevent diabetes and other health problems. Methods to assess chromium amounts in the body are lacking, but chromium is stored in hair and blood (serum). However, hair analysis is not a valid method to analyze nutritional status of chromium or any other nutrient.
It is relatively easy to get safe and adequate amounts of chromium (50-200 micrograms per day) by eating a variety of foods like brewer’s yeast, calf’s liver, American cheese and wheat germ.
People who take chromium picolinate supplements may suffer health problems rather than improved health. Although claims of weight loss, lowered cholesterol and reversal of diabetes are unfounded, researchers have shown that chromium supplements damaged cell chromosomes which are the blueprints for a cell’s function and reproduction. It is generally thought that cancer starts with a change to the genetic material in a cell causing it to grow and reproduce without restraint.
How effective and safe are Chromium Picolinate and Fenfluramine as appetite suppressants?
Chromium Picolinate is sold over the counter as a nutritional supplement. Chromium works with insulin in assisting cells to take in glucose and release energy. Chromium Picolinate has not been shown to cause weight loss and its ability to improve insulin effectiveness is being questioned.
Fenfluramine is the chemical name of a drug that inhibits the release of serotonin in the brain. Serotonin is the “feel good me” drug that the brain produces. Tryptophan (an amino acid found in complete proteins, especially turkey and chicken) is a precursor of serotonin. In addition, carbohydrates increase the serotonin levels in the brain. Exercise increases these neurotransmitters in the brain. Fenfluramine is being looked at as an anti-obesity drug. Research so far indicates that when the drug is stopped, weight can be regained. Ask you doctor about Fenfluramine.
Continue Reading about Chromium
July 6th, 2005
DSHEA broadened the regulatory definition of dietary supplements beyond essential vitamins, minerals, and amino acids, and even beyond other food constituents proposed to optimize nutrition. The definition includes, with some exceptions, any product intended for ingestion as a supplement to the diet, including vitamins, minerals, amino acids, herbs, botanicals, other plant-derived substances, and concentrates, metabolites, constituents, and extracts of these substances. Although regulated as dietary supplements, with associated labeling requirements that limit disease-related claims, some supplement products are marketed in third party “literature and information” for pharmacological, rather than nutritional, purposes, as “natural” treatments for diseases such as cancer, heart disease, AIDS, arthritis, diabetes and multiple sclerosis. Similar promotions make distinctions between nutritional and pharmacological properties especially difficult for some herbal products. Herbal teas are regulated as foods, and herbs promoted for pharmacological properties (in third party literature) may appear in products such as beverages, bars, and other foods.
Conventional foods and dietary supplements are not intended to treat disease. Dietitians’ recommendations should be for the purpose of improving nourishment (with essential nutrients as well as other potentially beneficial food components that may help prevent disease). For products intended to treat disease, registered dietitians must evaluate whether their academic preparation and scope of practice (including state licensing regulations for dietitians and other health care professionals) qualifies them to provide advice advocating the use of such products. Recommendations of dietary supplements to treat disease should be under a physician’s supervision, but dietitians must know about these products to help answer client questions, identify potential food and drug interactions, and document client use.
Dietetics professionals must recognize when to make appropriate medical referrals for the diagnosis and treatment of disease. For example, in the United States, St. John’s Wort (Hypericum) is marketed to help mood and depression. The supportive evidence for this product has been sufficient to justify several randomized, placebo-controlled, double-blind clinical trials now underway to evaluate the effectiveness of Hypericum in comparison with established antidepressant medications. At the same time, concerns have been raised about drug interactions with Hypericum, including the undesirable use of this supplement by HIV-infected patients treated with certain protease inhibitors. This product may be shown to be safe and effective under some conditions. But even though neighbors, friends, or sales personnel can recommend such a product, professional recommendations should be made only by professionals trained to differentially diagnose and treat depression, skills which are not in the training or scope of practice of dietetics.
Certain foods, statutorily classified as “medical foods” under the Food, Drug and Cosmetic Act (FDC Act), are intended and can be used as therapeutic dietary adjuncts to medical treatment. However, such products must provide a distinctive nutritional need that is related to the disease or medical condition that is based on sound science, and the products must be used under the care and advice of a physician. Formulas and foods that are low or absent in phenylalanine and oral rehydration solutions are examples of such medical foods.
July 5th, 2005
Should dietetics professionals advise general multivitamin-mineral supplements at modest doses to help meet dietary recommendations? As already indicated, a variety of good foods wisely selected is the basis of a nutritious diet, will meet dietary recommendations for most nutrients, and is the best way to assure a balance of nutrients and healthy food components for which no recommendations have been established. While there is little scientific evidence of benefit to the average person, there is also little evidence of harm from low-dose multivitamin or multivitamin-mineral supplements in amounts that do not exceed 100% of the RDA. The choice of either a multivitamin or highly fortified foods (such as some breakfast cereals) can be used to meet the new recommendations to increase synthetic sources of folic acid for women capable of becoming pregnant and synthetic sources of vitamin B-12 for older adults. Otherwise, recommendations for these groups can be met by using specific supplements providing folic acid or vitamin B-12, respectively.
Low-dose multivitamin-mineral supplements may provide benefit to those with limited dietary intakes. Such low-dose supplements improved indices of immune function and reduced infectious illness in a double-blind placebo-controlled investigation of 96 free-living Canadian elderly men and women. Similar supplements had no benefit in a double-blind placebo-controlled study of muscle weakness and physical frailty of 100 very elderly people in a Boston nursing home. More research in this area should be encouraged.
Professional recommendations to use low-dose multivitamin and mineral supplements should depend on individualized dietary assessments that consider how usual diets can be modified with food, fortification or supplemental sources of nutrients to meet individual needs. People using both highly fortified foods and multivitamins, even without other specific nutrient supplements can easily consume 300% of the RDA for many known nutrients. Some would question whether these high intakes of known nutrients are appropriately balanced with other health promoting components of food, many of which are unidentified. The goal should be to meet the RDA or AI while not exceeding the UL. As indicated by the Food and Nutrition Board, “there is no established benefit for healthy individuals if they consume a nutrient in amounts above the recommended intake (RDA or AI)”.
There is a special need for moderation under certain circumstances. For example, preformed vitamin A should not be taken in the first trimester of pregnancy. For men and postmenopausal women, who generally have adequate iron stores, supplemental iron, without a clinical assessment demonstrating low iron status, has little likelihood of benefit and may be of risk to those with certain genetic characteristics (see section on Toxicities, adverse nutrient interactions, and safety, p.x). In addition to evaluating total intakes for meeting and not greatly exceeding the Recommended Dietary Allowances, dietetics professionals should use the new UL designated by the Food and Nutrition Board to avoid dangerously excessive intakes.
July 5th, 2005
Healthy American adults should eat no more than 2,300 milligrams of sodium a day. This is about 1 teaspoon of sodium chloride (salt). To illustrate, the following are sources of sodium in the diet.
1/4 teaspoon salt = 600 mg sodium
1/2 teaspoon salt = 1,200 mg sodium
3/4 teaspoon salt = 1,800 mg sodium
1 teaspoon salt = 2,400 mg sodium
1 teaspoon baking soda = 1000 mg sodium
What are the common sources of sodium?
When you must reduce the amount of sodium (salt) you eat, be aware of both natural and added sodium content. Table salt is sodium chloride. It’s 40 percent sodium by weight. When you buy prepared and packaged foods, read the labels. Watch for the words “soda” (referring to sodium bicarbonate, or baking soda) and “sodium” and the symbol “Na.” These products contain sodium compounds.
Some drugs have high amounts of sodium. Carefully read the labels on all over-the-counter drugs. Look at the ingredient list and warning statement to see if the product has sodium. A statement of sodium content must be on labels of antacids that have 5 mg or more per dosage unit (tablet, teaspoon, etc.). Some companies are now producing low-sodium over-the-counter products. If in doubt, ask your doctor or pharmacist if the drug is OK for you.
Most spices naturally contain very small amounts of sodium.
How can I reduce the sodium in my diet?
* Choose fresh, frozen or canned food items without added salts.
* Select unsalted nuts or seeds, dried beans, peas and lentils.
* Limit the amount of salty snacks you eat, like chips and pretzels.
* Avoid adding salt and canned vegetables to homemade dishes.
* Select unsalted, fat-free broths, bouillons or soups.
* Select fat-free or low-fat milk, low-sodium, low-fat cheeses, as well as low-fat yogurt.
* Specify what you want and how you want it prepared when dining out. Ask for your dish to be prepared without salt.
* Use spices and herbs to enhance the taste of your food.
July 1st, 2005
Potassium is an element (and an electrolyte) that’s essential for the body’s growth and maintenance. It’s necessary to keep a normal water balance between the cells and body fluids. Potassium also plays an essential role in the response of nerves to stimulation and in the contraction of muscles. Cellular enzymes need potassium to work properly.
A potassium deficiency due to increased urinary loss often occurs when medication for certain heart diseases is used to prevent sodium and water retention. To overcome this loss, physicians often suggest eating more foods high in potassium. More potassium may be prescribed as a medicine.
Foods high in potassium include bananas, cantaloupe, grapefruit, oranges, tomato or prune juice, honeydew melons, prunes, molasses and potatoes. Some foods high in potassium are also high in calories. When weight control is important, eat more low-calorie foods. Foods such as fruits, vegetables and low-fat dairy products that are high in potassium and calcium, when incorporated in the DASH Diet Study, helped to significantly lower blood pressure.
July 1st, 2005
Many physicians encourage women to eat fat-free and low-fat dairy products to get
calcium. This helps reduce their risk of developing the bone disease osteoporosis. In this disease, the bone loses calcium and becomes less dense and breaks more easily.
AHA Recommendation
Women should ask their physicians about how much calcium they need in their diets. Fat-free milk and low-fat dairy products are recommended. They’re excellent sources of calcium.
Vegetable greens such as spinach, kale and broccoli, and some legumes and soybean products are good sources of calcium from plants.
Does calcium intake affect the risk of developing cardiovascular disease?
Right now scientists don’t have enough information to know. But the DASH Diet helped significantly to lower blood pressure. This study was based on eating eight or more fruits and vegetables and fat-free and low-fat dairy products.
Data from the National Academy of Sciences, Institute of Medicine, recommends that adequate daily intake be…
*200 mg for infants from birth to 6 months; 270 mg for ages 6 months to 1 year.
*500 mg for children ages 1–3; 800 mg for ages 4–8.
*1300 mg for children and adolescents ages 9–18.
*1000 mg for adults ages 19–30 (for maximal calcium retention); 1000 mg for adults ages 31–50 (for calcium balance).
*1200 mg for adults ages 51 and older.
*1300 mg for women who are pregnant and under age 19; 1000 mg for pregnant women ages 19–50.
July 1st, 2005
Vitamin K helps make six of the 13 proteins needed for blood clotting. Its role in maintaining the clotting cascade is so important that people who take anticoagulants such as warfarin (Coumadin) must be careful to keep their vitamin K intake stable.
Lately, researchers have demonstrated that vitamin K is also involved in building bone. Low levels of circulating vitamin K have been linked with low bone density, and supplementation with vitamin K shows improvements in biochemical measures of bone health. A report from the Nurses’ Health Study suggests that women who get at least 110 micrograms of vitamin K a day are 30% less likely to break a hip as women who get less than that. Among the nurses, eating a serving of lettuce or other green leafy vegetable a day cut the risk of hip fracture in half when compared with eating one serving a week. Data from the Framingham Heart Study also shows an association between high vitamin K intake and reduced risk of hip fracture.
Optimal Intake: The recommended daily intake for vitamin K is 80 micrograms for men and 65 for women. Because this vitamin is found in so many foods, especially green leafy vegetables and commonly used cooking oils, most adults get enough of it. According to a 1996 survey, though, a substantial number of Americans, particularly children and young adults, aren’t getting the vitamin K they need.
July 1st, 2005
For a time, vitamin E supplements looked like an easy way to prevent heart disease. Promising observational studies, including the Nurses’ Health Study and Health Professionals Follow-up Study, suggested 20% to 40% reductions in coronary heart disease risk among individuals who took vitamin E supplements (usually containing 400 IU or more) for least two years.
The results of several randomized trials have dampened enthusiasm for vitamin E’s ability to prevent heart attacks or deaths from heart disease among individuals with heart disease or those at high risk for it. In the GISSI Prevention Trial, the results were mixed but mostly showed no preventive effects after more than three years of treatment with vitamin E among 11,000 heart attack survivors. Results from the Heart Outcomes Prevention Evaluation (HOPE) trial also showed no benefit of four years worth of vitamin E supplementation among more than 9,500 men and women already diagnosed with heart disease or at high risk for it. Based on these and other studies, the American Heart Association has concluded that “the scientific data do not justify the use of antioxidant vitamin supplements [such as vitamin E] for CVD risk reduction.”
A recent scientific analysis raised questions about whether high doses of vitamin E supplements might increase the risk of dying.The authors gathered and re-analyzed data from 19 clinical trials of vitamin E, including the GISSI and HOPE studies; they found a higher rate of death in trials where patients consumed more than 400 IU of supplements per day. While this meta-analysis drew headlines when it was released online in November 2004, there are limitations to the conclusions that can be drawn from it. Some of the findings are based on very small studies; furthermore, many of the high-dose trials of Vitamin E included in the analysis were done on people who had chronic diseases, such as heart disease or Alzheimer’s disease. So it is not clear that these findings would apply to healthy people.
It’s entirely possible that in secondary prevention trials, the use of drugs such as aspirin, beta blockers, and ACE inhibitors mask a modest effect of vitamin E, and that it may have benefits among healthier people. Ongoing randomized trials of vitamin E, such as the Women’s Health Study and SU.VI.MAX will tell us more about its possible benefits in the coming years.
Vitamin E Optimal Intake: The recommended daily intake of vitamin E from food now stands at 15 milligrams from food. That’s the equivalent of 22 IU from natural-source vitamin E or 33 IUs of the synthetic form. Researchers are still writing the book on vitamin E. Some small studies have suggested that vitamin E supplements might interfere with statins, but this hypothesis was refuted in a large trial. While the data are sparse and conflicting, evidence from some observational studies suggests that at least 400 IU of vitamin E per day, and possibly more, are needed for optimal health. Since standard multivitamins usually contain around 30 IU, a separate vitamin E supplement is needed to achieve this level. Current guidelines say that consuming more than 1000 mg of supplemental vitamin E per day is not considered safe; that’s the equivalent of a supplement with 1,500 IU of natural-source vitamin E or 1,100 IU of synthetic vitamin E.
July 1st, 2005
If you live north of the line connecting San Francisco to Philadelphia, odds are you don’t get enough vitamin D. The same holds true if you don’t, or can’t, get outside for at least a 15-minute daily walk in the sun. African-Americans and others with dark skin tend to have much lower levels of vitamin D, due to less formation of the vitamin from the action of sunlight on skin. A study of people admitted to a Boston hospital, for example, showed that 57% were deficient in vitamin D.
Vitamin D helps ensure that the body absorbs and retains calcium and phosphorus, both critical for building bone. Laboratory studies also show that vitamin D keeps cancer cells from growing and dividing.
Some preliminary studies indicate that insufficient intake of vitamin D is associated with an increased risk of fractures, and that vitamin D supplementation may prevent them. It may also help prevent falls, a common problem that leads to substantial disability and death in older people. Other early studies suggest an association between low vitamin D intake and increased risks of prostate, breast, colon, and other cancers.
Vitamin D Optimal Intake: The current recommended intake of vitamin D is 5 micrograms up to age 50, 10 micrograms between the ages of 51 and 70, and 15 micrograms after age 70. Optimal intakes are higher, though, with 25 micrograms (1000 IU) recommended for those over age 2. Very few foods naturally contain vitamin D. Good sources include dairy products and breakfast cereals (which are fortified with vitamin D), and fatty fish such as salmon and tuna. For most people, the best way to get the recommended daily intake is by taking a multivitamin, but the level in most multivitamins (10 micrograms) is too low.
July 1st, 2005
Vitamin C has been in the public eye for a long time. Even before its discovery in 1932, nutrition experts recognized that something in citrus fruits could prevent scurvy, a disease that killed as many as 2 million sailors between 1500 and 1800. More recently, Nobel laureate Linus Pauling promoted daily megadoses of vitamin C (the amount in 12 to 24 oranges) as a way to prevent colds and protect the body from other chronic diseases.
There’s no question that vitamin C plays a role in controlling infections. It’s also a powerful antioxidant that can neutralize harmful free radicals, and it helps make collagen, a tissue needed for healthy bones, teeth, gums, and blood vessels. The question is, do you need lots of vitamin C to keep you healthy?
No. Vitamin C’s cold-fighting potential certainly hasn’t panned out. Small trials suggest that the amount of vitamin C in a typical multivitamin taken at the start of a cold might ease symptoms, but there’s no evidence that megadoses make a difference, or that they prevent colds. Studies of vitamin C and heart disease, cancer, and eye diseases such as cataract and macular degeneration also show no clear patterns.
Vitamin C Optimal Intake: The current recommended dietary intake for vitamin C is 90 mg for men and 75 mg for women (add an extra 35 mg for smokers). There’s no good evidence that megadoses of vitamin C improve health. As the evidence continues to unfold, 200 to 300 mg of vitamin C a day appears to be a good target. This is easy to hit with a good diet and a standard multivitamin. Excellent food sources of vitamin C are citrus fruits or citrus juices, berries, green and red peppers, tomatoes, broccoli, and spinach. Many breakfast cereals are also fortified with vitamin C.
July 1st, 2005
In addition to recycling homocysteine, folate plays a key role in building DNA, the complex compound that forms our genetic blueprint. Observational studies show that people who get higher than average amounts of folic acid from their diets or supplements have lower risks of colon cancer and breast cancer. This could be especially important for those who drink alcohol, since alcohol blocks the absorption of folic acid and inactivates circulating folate. An interesting observation from the Nurses’ Health Study is that high intake of folic acid blunts the increased risk of breast cancer seen among women who have more than one alcoholic drink a day.
Optimal Intake: The definition of a healthy daily intake of B vitamins isn’t set in stone, and is likely to change over the next few years as data from ongoing randomized trials are evaluated. Because only a fraction of U.S. adults currently get the recommended daily intake of B vitamins by diet alone, use of a multivitamin supplement will become increasingly important.
July 1st, 2005
In 1968, a Boston pathologist investigaed the deaths of two children from massive strokes. Both had inherited conditions that caused them to have high levels of a protein breakdown product called homocysteine in their blood, and both had arteries as clogged with cholesterol as those of a 65-year-old fast food addict. Putting one and one together, he hypothesized that high levels of homocysteine contribute to the artery-clogging process of atherosclerosis. Since then, some-but not all-studies have linked high levels of this breakdown product, called homocysteine, with increased risks of heart disease and stroke.
Folic acid, vitamin B6, and vitamin B12 play key roles in recycling homocysteine into methionine, one of the 20 or so building blocks from which the body builds new proteins. Without enough folic acid, vitamin B6, and vitamin B12, this recycling process becomes inefficient and homocysteine levels increase. Several observational studies show that high levels of homocysteine are associated with increased risks of heart disease and stroke. Increasing intake of folic acid, vitamin B6, and vitamin B12 decreases homocysteine levels. And some observational studies show lower risks of cardiovascular disease among people with higher intakes of folic acid, those who use multivitamin supplements, or those with higher levels of serum folate (the form of folic acid found in the body). However, other prospective studies show little or no association between homocysteine and cardiovascular disease.
The first large trial of homocysteine to be completed ended with negative results. In the Vitamin Intervention for Stroke Prevention trial, 3680 adults who had had nondisabling strokes took a pill containing high doses of vitamins B6, B12, and folic acid or one containing low doses of these three B vitamins. After two years, second strokes, heart attacks and other coronary heart disease events, and deaths were the same in the two groups. However, in that trial, high levels of homocysteine at baseline were associated with higher risk of cardiovascular disease. Other ongoing randomized trials, such as the Women’s Antioxidant Cardiovascular Study and the Vitamin Intervention in Stroke Prevention Study should yield more definitive answers regarding homocysteine, B vitamins, and cardiovascular risk.
July 1st, 2005
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