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ConsumerLab.com Answers
Question: Being over 50 years old, I'm looking to take a vitamin B-12 supplement. I see that many contain a form of vitamin B-12 called cyanocobalamin, yet I read on the Internet that this form is toxic. Should I be concerned?
Answer: The most common form of B-12 in vitamin supplements is cyanocobalamin and although this form includes a cyanide molecule, it is very safe. Why? Even at a very high dose, it would provide about a thousand times less cyanide than is toxic, and the cyanide is excreted in the urine. B-12 is also available in supplements as methylcobalamin. Supplements with both types of B-12 are included in the Product Review of B Vitamins.
ConsumerLab.com Answers
Question: Can vitamin supplements strengthen brittle nails?
Answer:
There are many supplements marketed for strengthening nails, but the only significant evidence to-date is for supplementing with biotin (vitamin B-7). A small, but controlled, study among women with brittle nails found that a daily dose of 2,500 mcg of biotin for 6 to 9 months increased nail thickness by 25% and reduced the tendency of nails to split (Columbo, J Am Acad Dermatol 1990). Biotin does not, however, further strengthen healthy nails. ConsumerLab.com's tests of biotin supplements are found in the Product Review of B Vitamins.
Some preliminary studies also suggest improvement in brittle nails supplementing with 10 to 30 mL daily of colloidal silicon (silicic acid, trademarked Silicol) or 10 mg daily of orthosilicic acid. Adequate intake of vitamins and minerals facilitates nail health, but there is no evidence that normal nails are affected by supplementing with gelatin, collagen, cystine, L-methionine, keratin, pantothenic acid, salt, millet, yeast, or chromium, or with formulas containing these ingredients (Scheinfeld J Drugs Dermatol 2007).
ConsumerLab.com Answers
Question: Is it better to get vitamins from foods or supplements, and are natural vitamins better than synthetic vitamins?
Answer:
It is generally best to get your vitamins (as well as minerals) naturally from foods or, in the case of vitamin D, controlled sun exposure. For example, recent research on the mineral calcium suggests that it is safest to get your calcium from foods that are naturally rich in calcium than from supplements. Older women who get high amounts of calcium from supplements seem to have a higher risk of kidney stones, strokes, and even a greater risk of dying over periods of time. A small increased risk of death has also been seen in studies of people taking supplements containing vitamin A and beta-carotene compared to those who did not.
Exceptions to the "foods are better" rule are two B vitamins. Ten to thirty percent of older people don't properly digest and absorb natural vitamin B-12 from foods, so it is recommended to get B-12 from a supplement if you are over age 50. Folic acid (vitamin B-9) from supplements and fortified foods is absorbed twice as well as from regular food. Consequently, pregnant woman are advised to get folic acid from a supplement (or fortified food) as well as regular foods. Also keep in mind that if you get your iron from plant foods, it is absorbed only half as well as iron from meat -- although eating your spinach (or iron supplement) with a source of vitamin C will boost the absorption of its iron.
Using supplements made from whole foods won't necessarily give you more vitamins (in fact, they typically contain more modest amounts of vitamins than other dietary supplements), but you will get other plant compounds which could be of potential benefit (as well as some grams of fiber if you are consuming, for example, spoonfuls of a whole food powder as opposed to a pill). Paying a premium price for this, however, may not be worthwhile and ConsumerLab.com has found lead contamination in some whole food and "greens" products.
Regarding natural vs. synthetic forms of vitamins in dietary supplements, sometimes natural is better, sometimes synthetic is better, and sometimes it doesn't matter. Keep in mind that all can help prevent or treat deficiencies and other conditions, and nearly all are known to be harmful at too high a dose.
Natural may be better in the case of vitamin E. At low doses, either natural (d-alpha-tocopherol) or synthetic (dl-alpha-tocopherol) can be fine, although you need more IUs of synthetic (1.6 IU) to get the same amount of active vitamin E as from 1 IU of natural vitamin E. There is also a greater risk of bleeding problems with synthetic vitamin E at high doses, so that the upper limit for vitamin E for adults is 1,100 IU of synthetic vitamin E, but 1,500 IU of natural vitamin E. Naturally, vitamin E also contains other tocopherols and tocotrienols, which may have benefit. However, ConsumerLab.com tests show that not all "natural" vitamin E products contain these additional natural compounds.
Natural may also be better with vitamin K. A form of vitamin K-2, known as MK-7, naturally derived from fermented soy beans and used in supplements is better at raising vitamin K levels than supplements with synthetic K-1 or synthetic K-2, known as MK-4.
Natural or synthetic sources are both fine for getting vitamin C. Rose hips or acerola or synthetically produced vitamin C all provide the same compound -- ascorbic acid. The inclusion of citrus bioflavonoids (naturally present or added) may improve absorption.
Sometimes synthetic forms of vitamins offer advantages over natural forms. A synthetic form of niacin (vitamin B-3) called inositol hexanicotinate, for example, causes less flushing of the skin than niacin.
Use the links above to get more information about each vitamin or mineral, including ConsumerLab.com's tests and reviews of supplements containing those nutrients. For recommended daily intakes of these and other vitamins and minerals also see the Recommended Daily Intake tables, which includes upper intake limits.
ConsumerLab.com Answers
Question: What is Metafolin (5-methylfolate)? I see it in some supplements instead of folic acid. Is it better than folic acid?
Answer:
Supplements have typically provided folic acid as their source of folate -- an essential B vitamin. In 2001 and 2010, respectively, Metafolin and Quatrefolic were approved in the U.S. as sources of folate in supplements. These two ingredients have some advantages compared to folate from foods and folic acid, and they differ somewhat from each other. You can get details about these ingredients in the section on Folate in the B Vitamins Review >>
Question: If I already take red yeast rice, would adding high-dose niacin help further reduce my cholesterol levels, and would this be safe?
Answer: Red yeast rice is effective because it naturally contains cholesterol-lowering "statin" compounds, such as lovastatin. However, studies in which statin drugs have been given with high-dose niacin therapy suggest that this is not a helpful combination for most people and there are safety concerns. The same issues are likely to arise with the combination of red yeast rice and high-dose niacin therapy, so this combination would not seem advisable. For more details about the effects of statins given with high-dose niacin, see the Niacin section of the B Vitamins Product Review (which includes our tests of niacin and other B vitamins) >>.
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Product Review:B Vitamin Supplements and Energy Drinks (Including B Complexes, Niacin, B-6, B-12, Biotin, Thiamin, and Folic Acid)
Posted: 9/23/12 Updated: 12/14/13
Tests Show Many B-Complex Supplements and "Energy" Drinks Contain Wrong Amounts of Vitamins
Find Out Now If Yours Passed!
B vitamin supplements and energy drinks in this review (including B-complexes, thiamin, niacin, vitamin B-6, vitamin B-12, biotin, folate, and pantothenic acid supplements):
Our tests and quality ratings of B vitamin supplements, including B-complexes and energy drinks/shots, revealed problems with the quality of 7 out of 23 products selected for review. These products came up short on listed vitamins, containing only 31% to 87% of the claimed amounts, and/or contained far more ingredient than claimed, ranging from 182% to 230% of what was expected. Among B vitamin supplements, the most problematic were B complexes.
Testing also revealed the actual amounts of caffeine in the popular energy drinks/shots 5-Hour Energy, Monster Energy M-3, and Red Bull. Just a single small bottle of either of two of these products contained more than twice the caffeine you would expect from a regular cup of coffee. Following the serving suggestions of one product could lead you to ingest an extremely high amount of caffeine -- over 600 mg per day.
In this comprehensive report, you'll get quality ratings and reviews of 37 B vitamin supplements and fortified energy drinks: 23 products selected by ConsumerLab.com and 14 others that passed voluntary certification testing. You'll also get information about two supplements similar to one that passed testing. Tested products include B-complexes, energy shots, and single-B vitamin supplements with thiamin, niacin, vitamin B-6, vitamin B-12, biotin, folate (folic acid), or pantothenic acid.
In this comprehensive report, you'll discover:
Which B vitamin supplements and energy drinks Iailed testing and which passed
Direct comparisons and quality ratings of B vitamin supplements and energy drinks
Information on what B vitamin supplements and energy drinks can and cannot do for you -- some may reduce memory decline!
Important differences between forms of B vitamins, such as those of niacin: nicotinic acid, niacinamide, inositol hexanicotinate, and delayed-release formulations.
Usage and dosage information for the B vitamins thiamin, niacin, vitamin B-6, B-12, biotin, folate (folic acid), and pantothenic acid.
Side effects and potential drug interactions with B vitamins
Safety concerns about energy drinks and how to use them more safely, including concern over ingredients such as L-carnitine
ConsumerLab.com Answers -- for B Vitamin Supplements and Energy Drinks (Including B Complexes, Niacin, B-6, B-12, Biotin, Thiamin, and Folic Acid)
Question: Being over 50 years old, I'm looking to take a vitamin B-12 supplement. I see that many contain a form of vitamin B-12 called cyanocobalamin, yet I read on the Internet that this form is toxic. Should I be concerned? Get the answer >>
Question: Can vitamin supplements strengthen brittle nails? Get the answer >>
Question: Is it better to get vitamins from foods or supplements, and are natural vitamins better than synthetic vitamins? Get the answer >>
Question: What is Metafolin (5-methylfolate)? I see it in some supplements instead of folic acid. Is it better than folic acid? Get the answer >>
Question: If I already take red yeast rice, would adding high-dose niacin help further reduce my cholesterol levels, and would this be safe? Get the answer >>
