nail strengthening supplements
Can vitamin supplements strengthen brittle nails?
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).