Long, strong, beautiful nails! They are nearly synonymous with good health and feminine sex appeal. Whether or not they actually drive men wild, they do drive many women to health and vitamin stores and sites as well as nail salons in their quest to grow their own or buy fake ones. In 3 weeks you'll be less wrinkly, more shiny and stronger in the nail department.” Sounds pretty promising, right? This enticing promise is from www.beautyscoop.com, the first Web site hit on Google after typing in “nail supplements.” Backed by celebrities and featured in on-trend magazines, this liquid supplement (BeautyScoop ) has vitamin E, calcium, soy oil, biotin, zinc and a lot of other vitamins and minerals and costs $95 for a 21-day supply. That’s a lot of money for a product that has no peer-reviewed quality science behind it! START WITH HEALTHY NAILS Nail supplements are everywhere and the Internet and magazines are full of claims for certain “natural” remedies that are supposed to make one’s nails strong and beautiful. A common question many patients ask their doctors is, “What can I take that will make my nails stronger?” The answer to this is essentially nothing, unless your patient does not already have normal, healthy nails to begin with. WEIGHING THE OPTIONS Following are brief summaries of the most common supplements marketed for nail strength and growth. Vitamins Biotin (Vitamin H) — This is probably the vitamin that comes to mind first when people think about nails. It is also the most heavily marketed toward consumers for the purpose of building strong and healthy nails. What is biotin? It is a water-soluble vitamin classified as a B-complex vitamin and is involved in crucial metabolic processes along with glucose, fatty acids and amino acids. Biotin is required by all organisms, but it can be synthesized only by bacteria, yeasts, molds, algae and some plant species.1-2 Biotin is found in many foods, but generally in lower amounts than other water-soluble vitamins. Egg yolks, yeast, nuts and soybeans are rich sources of biotin.1-2 The finding that biotin supplements were effective in treating hoof abnormalities in horses led to speculation that biotin supplements might also be helpful in strengthening brittle fingernails in humans./3 Biotin has shown to be effective in treating individuals with brittle nail syndrome as characterized by dry, soft, easily breakable nails that show onychorrhexis and onychoschizia.4-6 Biotin supplementation has not been proven to increase nail strength or growth in individuals who are healthy, well-nourished and have normal nails to begin with. Vitamin D — Well-known for its proven, positive effects on bone health, many other physiologic functions are affected in a positive way by this vitamin. Unfortunately, healthy nails are not among them. Calcipotriol is a vitamin-D derivative that has been studied in healthy and psoriatic nails. While it is efficacious in improving nail psoriasis, it does not improve the strength, growth or appearance of normal, healthy nails.7-10 Vitamin E — There is no evidence suggesting that vitamin E supplementation enhances healthy nails. However, there are a few small studies suggesting possible improvement of individuals with yellow nail syndrome with topical and high-dose oral vitamin E consumption (600 IU to 1200 IU).11-12 Vitamin B12 — There are two reports of nail hyperpigmentation associated with vitamin B12 deficiency that resolved after supplementation,13-14 but there are no studies existing regarding vitamin B12 and enhancement of nail health in already normal nails. Minterals Minerals associated with nail enhancement include calcium, iron, zinc, selenium and silicon. These are all trace elements, so called because they are required by the human body in such small amounts. Because of this, toxicity can result from excessive supplementation, so it is a good idea to warn your patients about this if they are taking supplemental trace elements. There are no studies demonstrating enhanced nail strength or appearance in already healthy nails with mineral supplementation. However, severe deficiencies of calcium, iron, and zinc have been reported to negatively affect nail health and lead to nail changes that often reverse after supplementation with the deficient mineral.15-19 Excessive selenium supplementation leading to toxicity has been associated with longitudinal streaks or yellowish-white lines on the nail plate.20-21 A few reports exist demonstrating improvement with silicon supplementation for individuals with brittle nails and psoriatic nails.22-23 Fatty Acids While the omega-3 fatty acids EPA and DHA have well-established health benefits for the cardiovascular and neurological systems, they have not been studied regarding nail disease or enhancement of normal nail health. WHAT TO TELL YOUR PATIENTS There is no evidence suggesting the use of vitamin or mineral supplementation for improving nail health in healthy, well-nourished individuals who already have normal nails. • Eat a balanced diet. — A healthy, well-balanced diet consisting of an adequate daily intake of vitamins and minerals facilitates nail health in general. • Practice good nail habits. — It is a good idea to advise your patients to practice good nail habits such as: • Avoiding long-term exposure to water (ie, frequent dish washing) • Not overusing nail polish remover (very drying to nails and cuticles) • Not over-manicuring • Not biting or picking at nails and cuticles • Avoiding acrylic/artificial nails • Using a moisturizing cream or oil on the nails after washing and bathing • Use supplements for nutritional deficiencies. — Certain conditions such as brittle nail syndrome and nutritional deficiencies benefit from supplementation with the associated nutrient (ie, biotin in brittle nail syndrome and nail changes from mineral deficiencies). • Be aware of nail-related symptoms of underlying disease. — Also, ask your patients about systemic signs and symptoms that may offer a clue to an internal process that could be affecting nail health such as diabetes, liver or thyroid disease. For further reading, please review the following excellent article: Scheinfeld N, Dahdah M, Scher R. Vitamins and minerals: their role in nail health and disease. J Drugs Dermatol. 2007;6(8):782-7. Dr. Taylor, a Fellow in the Department of Dermatology at Wake Forest University Baptist Medical Center in Winston-Salem, NC, is board-certified in Family Medicine, which she practices in Winston-Salem, NC. References 1. Fernandez-Mejia C. Pharmacological effects of biotin. J Nutr Biochem. 2005;16:424-427. 2. National Library of Medicine, National Institutes of Health. Biotin (Vitamin H). https://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-biotin.html. Accessed 12/5/2009. 3. Reilly JD, Cottrell DF, Martin RJ, Cuddeford DJ. Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial. Equine Vet J. 1998;26:51-57. 4. Floersheim GL. [Treatment of brittle fingernails with biotin]. Z Hautkr. 1989;64(1):41-48. 5. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis. 1993;51(4):303-305. 6. Uyttendaele H, Geyer A, Scher RK.Brittle nails: pathogenesis and treatment. J Drugs Dermatol. 2003;2:48-49. 7. Hogan DB, McNair S, Young J, Crilly RG. Nail growth, calcium, and vitamin D. Ann Intern Med. 1984;101:283. 8. Totsi A, Piraccini BM, Cameli N, et al. Calcipotriol ointment in nail psoriasis: a controlled double-blind comparison with betamethasone dipropionate and salicylic acid. Br J Dermatol.1998;139:655-659. 9. Zakeri M, Valikhani M, Mortazavi H, Barzegari M. Topical calcipotriol therapy in nail psoriasis: a study of 24 cases. Dermatol Online J. 2005;11:5. 10. Piraccini BM, Tosti A, Iorizzo M, Misciali C. Pustular psoriasis of the nails: treatment and long-term follow-up of 46 patients. Br J Dermatol. 2001;144:1000-1005. 11. Williams HC, Buffham R, du Vivier A. Successful use of topical vitamin E solution in the treatment of nail changes in yellow nail syndrome. Arch Dermatol. 1991;127:1023-1028. 12. Ayres S Jr, Mihan R. Yellow nail syndrome: response to Vitamin E. Arch Dermatol. 1973;108:267-268. 13. Ridley CM. Pigmentation of fingertips and nails in vitamin B12 deficiency. Br J Dermatol. 1977;97:105-106. 14. Noppakun N, Swasdikul D. Reversible hyperpigmentation of skin and nails with white hair due to vitamin B12 deficiency. Arch Dermatol. 1986;12:896-899. 15. Foti C, Cassano N, Palmieri VO, et al. Transverse leukonychia in severe hypocalcemia. Eur J Dermatol. 2004;14:67-68. 16. Kumar G, Vaidyanathan L, Stead LG. Images in emergency medicine. Koilonychia, or spoon-shaped nails nails, is generally associated with iron-deficiency anemia.Ann Emerg Med. 2007;49(2):243-250. 17. Weismann K. Lines of Beau: possible markers of zinc deficiency. Acta Dermato-Venereol. 1977;57:88-90. 18. Reich H, Opitz K Bertram HP, Fegeler K. Successful zinc treatment of a severe case of acrodermatitis enteropathica. Dtsch Med Wochenschr. 1976;101:1724-1726. 19. Arroyo JF, Cohen ML. Improvement of yellow nail syndrome with oral zinc supplementation. Clin Exp Dermatol. 1993;18:62-64. 20. Longnecker MP, Stampfer MJ, Morris JS, et al. A 1-y trial of the effect of high-selenium bread on selenium concentrations in blood and toenails. Am J Clin Nutr. 1993;57:408-413. 21. Reid ME, Stratton MS, Lillico AJ, et al. A report of high-dose selenium supplementation: response and toxicities. J Trace Elem Med Biol. 2004;18:69-74. 22. Lassus A. Colloidal silicic acid for oral and topical treatment of aged skin, fragile hair and brittle nails in females. J Int Med Res.1993;21(4):209-15. 23. Lassus A. Colloidal silicic acid for the treatment of psoriatic skin lesions, arthropathy and oncyhopathy: A pilot study. J Int Med Res. 1997;25:206-209.
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Nails and Vitamin Supplementation
Long, strong, beautiful nails! They are nearly synonymous with good health and feminine sex appeal. Whether or not they actually drive men wild, they do drive many women to health and vitamin stores and sites as well as nail salons in their quest to grow their own or buy fake ones. In 3 weeks you'll be less wrinkly, more shiny and stronger in the nail department.” Sounds pretty promising, right? This enticing promise is from www.beautyscoop.com, the first Web site hit on Google after typing in “nail supplements.” Backed by celebrities and featured in on-trend magazines, this liquid supplement (BeautyScoop ) has vitamin E, calcium, soy oil, biotin, zinc and a lot of other vitamins and minerals and costs $95 for a 21-day supply. That’s a lot of money for a product that has no peer-reviewed quality science behind it! START WITH HEALTHY NAILS Nail supplements are everywhere and the Internet and magazines are full of claims for certain “natural” remedies that are supposed to make one’s nails strong and beautiful. A common question many patients ask their doctors is, “What can I take that will make my nails stronger?” The answer to this is essentially nothing, unless your patient does not already have normal, healthy nails to begin with. WEIGHING THE OPTIONS Following are brief summaries of the most common supplements marketed for nail strength and growth. Vitamins Biotin (Vitamin H) — This is probably the vitamin that comes to mind first when people think about nails. It is also the most heavily marketed toward consumers for the purpose of building strong and healthy nails. What is biotin? It is a water-soluble vitamin classified as a B-complex vitamin and is involved in crucial metabolic processes along with glucose, fatty acids and amino acids. Biotin is required by all organisms, but it can be synthesized only by bacteria, yeasts, molds, algae and some plant species.1-2 Biotin is found in many foods, but generally in lower amounts than other water-soluble vitamins. Egg yolks, yeast, nuts and soybeans are rich sources of biotin.1-2 The finding that biotin supplements were effective in treating hoof abnormalities in horses led to speculation that biotin supplements might also be helpful in strengthening brittle fingernails in humans./3 Biotin has shown to be effective in treating individuals with brittle nail syndrome as characterized by dry, soft, easily breakable nails that show onychorrhexis and onychoschizia.4-6 Biotin supplementation has not been proven to increase nail strength or growth in individuals who are healthy, well-nourished and have normal nails to begin with. Vitamin D — Well-known for its proven, positive effects on bone health, many other physiologic functions are affected in a positive way by this vitamin. Unfortunately, healthy nails are not among them. Calcipotriol is a vitamin-D derivative that has been studied in healthy and psoriatic nails. While it is efficacious in improving nail psoriasis, it does not improve the strength, growth or appearance of normal, healthy nails.7-10 Vitamin E — There is no evidence suggesting that vitamin E supplementation enhances healthy nails. However, there are a few small studies suggesting possible improvement of individuals with yellow nail syndrome with topical and high-dose oral vitamin E consumption (600 IU to 1200 IU).11-12 Vitamin B12 — There are two reports of nail hyperpigmentation associated with vitamin B12 deficiency that resolved after supplementation,13-14 but there are no studies existing regarding vitamin B12 and enhancement of nail health in already normal nails. Minterals Minerals associated with nail enhancement include calcium, iron, zinc, selenium and silicon. These are all trace elements, so called because they are required by the human body in such small amounts. Because of this, toxicity can result from excessive supplementation, so it is a good idea to warn your patients about this if they are taking supplemental trace elements. There are no studies demonstrating enhanced nail strength or appearance in already healthy nails with mineral supplementation. However, severe deficiencies of calcium, iron, and zinc have been reported to negatively affect nail health and lead to nail changes that often reverse after supplementation with the deficient mineral.15-19 Excessive selenium supplementation leading to toxicity has been associated with longitudinal streaks or yellowish-white lines on the nail plate.20-21 A few reports exist demonstrating improvement with silicon supplementation for individuals with brittle nails and psoriatic nails.22-23 Fatty Acids While the omega-3 fatty acids EPA and DHA have well-established health benefits for the cardiovascular and neurological systems, they have not been studied regarding nail disease or enhancement of normal nail health. WHAT TO TELL YOUR PATIENTS There is no evidence suggesting the use of vitamin or mineral supplementation for improving nail health in healthy, well-nourished individuals who already have normal nails. • Eat a balanced diet. — A healthy, well-balanced diet consisting of an adequate daily intake of vitamins and minerals facilitates nail health in general. • Practice good nail habits. — It is a good idea to advise your patients to practice good nail habits such as: • Avoiding long-term exposure to water (ie, frequent dish washing) • Not overusing nail polish remover (very drying to nails and cuticles) • Not over-manicuring • Not biting or picking at nails and cuticles • Avoiding acrylic/artificial nails • Using a moisturizing cream or oil on the nails after washing and bathing • Use supplements for nutritional deficiencies. — Certain conditions such as brittle nail syndrome and nutritional deficiencies benefit from supplementation with the associated nutrient (ie, biotin in brittle nail syndrome and nail changes from mineral deficiencies). • Be aware of nail-related symptoms of underlying disease. — Also, ask your patients about systemic signs and symptoms that may offer a clue to an internal process that could be affecting nail health such as diabetes, liver or thyroid disease. For further reading, please review the following excellent article: Scheinfeld N, Dahdah M, Scher R. Vitamins and minerals: their role in nail health and disease. J Drugs Dermatol. 2007;6(8):782-7. Dr. Taylor, a Fellow in the Department of Dermatology at Wake Forest University Baptist Medical Center in Winston-Salem, NC, is board-certified in Family Medicine, which she practices in Winston-Salem, NC. References 1. Fernandez-Mejia C. Pharmacological effects of biotin. J Nutr Biochem. 2005;16:424-427. 2. National Library of Medicine, National Institutes of Health. Biotin (Vitamin H). https://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-biotin.html. Accessed 12/5/2009. 3. Reilly JD, Cottrell DF, Martin RJ, Cuddeford DJ. Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial. Equine Vet J. 1998;26:51-57. 4. Floersheim GL. [Treatment of brittle fingernails with biotin]. Z Hautkr. 1989;64(1):41-48. 5. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis. 1993;51(4):303-305. 6. Uyttendaele H, Geyer A, Scher RK.Brittle nails: pathogenesis and treatment. J Drugs Dermatol. 2003;2:48-49. 7. Hogan DB, McNair S, Young J, Crilly RG. Nail growth, calcium, and vitamin D. Ann Intern Med. 1984;101:283. 8. Totsi A, Piraccini BM, Cameli N, et al. Calcipotriol ointment in nail psoriasis: a controlled double-blind comparison with betamethasone dipropionate and salicylic acid. Br J Dermatol.1998;139:655-659. 9. Zakeri M, Valikhani M, Mortazavi H, Barzegari M. Topical calcipotriol therapy in nail psoriasis: a study of 24 cases. Dermatol Online J. 2005;11:5. 10. Piraccini BM, Tosti A, Iorizzo M, Misciali C. Pustular psoriasis of the nails: treatment and long-term follow-up of 46 patients. Br J Dermatol. 2001;144:1000-1005. 11. Williams HC, Buffham R, du Vivier A. Successful use of topical vitamin E solution in the treatment of nail changes in yellow nail syndrome. Arch Dermatol. 1991;127:1023-1028. 12. Ayres S Jr, Mihan R. Yellow nail syndrome: response to Vitamin E. Arch Dermatol. 1973;108:267-268. 13. Ridley CM. Pigmentation of fingertips and nails in vitamin B12 deficiency. Br J Dermatol. 1977;97:105-106. 14. Noppakun N, Swasdikul D. Reversible hyperpigmentation of skin and nails with white hair due to vitamin B12 deficiency. Arch Dermatol. 1986;12:896-899. 15. Foti C, Cassano N, Palmieri VO, et al. Transverse leukonychia in severe hypocalcemia. Eur J Dermatol. 2004;14:67-68. 16. Kumar G, Vaidyanathan L, Stead LG. Images in emergency medicine. Koilonychia, or spoon-shaped nails nails, is generally associated with iron-deficiency anemia.Ann Emerg Med. 2007;49(2):243-250. 17. Weismann K. Lines of Beau: possible markers of zinc deficiency. Acta Dermato-Venereol. 1977;57:88-90. 18. Reich H, Opitz K Bertram HP, Fegeler K. Successful zinc treatment of a severe case of acrodermatitis enteropathica. Dtsch Med Wochenschr. 1976;101:1724-1726. 19. Arroyo JF, Cohen ML. Improvement of yellow nail syndrome with oral zinc supplementation. Clin Exp Dermatol. 1993;18:62-64. 20. Longnecker MP, Stampfer MJ, Morris JS, et al. A 1-y trial of the effect of high-selenium bread on selenium concentrations in blood and toenails. Am J Clin Nutr. 1993;57:408-413. 21. Reid ME, Stratton MS, Lillico AJ, et al. A report of high-dose selenium supplementation: response and toxicities. J Trace Elem Med Biol. 2004;18:69-74. 22. Lassus A. Colloidal silicic acid for oral and topical treatment of aged skin, fragile hair and brittle nails in females. J Int Med Res.1993;21(4):209-15. 23. Lassus A. Colloidal silicic acid for the treatment of psoriatic skin lesions, arthropathy and oncyhopathy: A pilot study. J Int Med Res. 1997;25:206-209.
Long, strong, beautiful nails! They are nearly synonymous with good health and feminine sex appeal. Whether or not they actually drive men wild, they do drive many women to health and vitamin stores and sites as well as nail salons in their quest to grow their own or buy fake ones. In 3 weeks you'll be less wrinkly, more shiny and stronger in the nail department.” Sounds pretty promising, right? This enticing promise is from www.beautyscoop.com, the first Web site hit on Google after typing in “nail supplements.” Backed by celebrities and featured in on-trend magazines, this liquid supplement (BeautyScoop ) has vitamin E, calcium, soy oil, biotin, zinc and a lot of other vitamins and minerals and costs $95 for a 21-day supply. That’s a lot of money for a product that has no peer-reviewed quality science behind it! START WITH HEALTHY NAILS Nail supplements are everywhere and the Internet and magazines are full of claims for certain “natural” remedies that are supposed to make one’s nails strong and beautiful. A common question many patients ask their doctors is, “What can I take that will make my nails stronger?” The answer to this is essentially nothing, unless your patient does not already have normal, healthy nails to begin with. WEIGHING THE OPTIONS Following are brief summaries of the most common supplements marketed for nail strength and growth. Vitamins Biotin (Vitamin H) — This is probably the vitamin that comes to mind first when people think about nails. It is also the most heavily marketed toward consumers for the purpose of building strong and healthy nails. What is biotin? It is a water-soluble vitamin classified as a B-complex vitamin and is involved in crucial metabolic processes along with glucose, fatty acids and amino acids. Biotin is required by all organisms, but it can be synthesized only by bacteria, yeasts, molds, algae and some plant species.1-2 Biotin is found in many foods, but generally in lower amounts than other water-soluble vitamins. Egg yolks, yeast, nuts and soybeans are rich sources of biotin.1-2 The finding that biotin supplements were effective in treating hoof abnormalities in horses led to speculation that biotin supplements might also be helpful in strengthening brittle fingernails in humans./3 Biotin has shown to be effective in treating individuals with brittle nail syndrome as characterized by dry, soft, easily breakable nails that show onychorrhexis and onychoschizia.4-6 Biotin supplementation has not been proven to increase nail strength or growth in individuals who are healthy, well-nourished and have normal nails to begin with. Vitamin D — Well-known for its proven, positive effects on bone health, many other physiologic functions are affected in a positive way by this vitamin. Unfortunately, healthy nails are not among them. Calcipotriol is a vitamin-D derivative that has been studied in healthy and psoriatic nails. While it is efficacious in improving nail psoriasis, it does not improve the strength, growth or appearance of normal, healthy nails.7-10 Vitamin E — There is no evidence suggesting that vitamin E supplementation enhances healthy nails. However, there are a few small studies suggesting possible improvement of individuals with yellow nail syndrome with topical and high-dose oral vitamin E consumption (600 IU to 1200 IU).11-12 Vitamin B12 — There are two reports of nail hyperpigmentation associated with vitamin B12 deficiency that resolved after supplementation,13-14 but there are no studies existing regarding vitamin B12 and enhancement of nail health in already normal nails. Minterals Minerals associated with nail enhancement include calcium, iron, zinc, selenium and silicon. These are all trace elements, so called because they are required by the human body in such small amounts. Because of this, toxicity can result from excessive supplementation, so it is a good idea to warn your patients about this if they are taking supplemental trace elements. There are no studies demonstrating enhanced nail strength or appearance in already healthy nails with mineral supplementation. However, severe deficiencies of calcium, iron, and zinc have been reported to negatively affect nail health and lead to nail changes that often reverse after supplementation with the deficient mineral.15-19 Excessive selenium supplementation leading to toxicity has been associated with longitudinal streaks or yellowish-white lines on the nail plate.20-21 A few reports exist demonstrating improvement with silicon supplementation for individuals with brittle nails and psoriatic nails.22-23 Fatty Acids While the omega-3 fatty acids EPA and DHA have well-established health benefits for the cardiovascular and neurological systems, they have not been studied regarding nail disease or enhancement of normal nail health. WHAT TO TELL YOUR PATIENTS There is no evidence suggesting the use of vitamin or mineral supplementation for improving nail health in healthy, well-nourished individuals who already have normal nails. • Eat a balanced diet. — A healthy, well-balanced diet consisting of an adequate daily intake of vitamins and minerals facilitates nail health in general. • Practice good nail habits. — It is a good idea to advise your patients to practice good nail habits such as: • Avoiding long-term exposure to water (ie, frequent dish washing) • Not overusing nail polish remover (very drying to nails and cuticles) • Not over-manicuring • Not biting or picking at nails and cuticles • Avoiding acrylic/artificial nails • Using a moisturizing cream or oil on the nails after washing and bathing • Use supplements for nutritional deficiencies. — Certain conditions such as brittle nail syndrome and nutritional deficiencies benefit from supplementation with the associated nutrient (ie, biotin in brittle nail syndrome and nail changes from mineral deficiencies). • Be aware of nail-related symptoms of underlying disease. — Also, ask your patients about systemic signs and symptoms that may offer a clue to an internal process that could be affecting nail health such as diabetes, liver or thyroid disease. For further reading, please review the following excellent article: Scheinfeld N, Dahdah M, Scher R. Vitamins and minerals: their role in nail health and disease. J Drugs Dermatol. 2007;6(8):782-7. Dr. Taylor, a Fellow in the Department of Dermatology at Wake Forest University Baptist Medical Center in Winston-Salem, NC, is board-certified in Family Medicine, which she practices in Winston-Salem, NC. References 1. Fernandez-Mejia C. Pharmacological effects of biotin. J Nutr Biochem. 2005;16:424-427. 2. National Library of Medicine, National Institutes of Health. Biotin (Vitamin H). https://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-biotin.html. Accessed 12/5/2009. 3. Reilly JD, Cottrell DF, Martin RJ, Cuddeford DJ. Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial. Equine Vet J. 1998;26:51-57. 4. Floersheim GL. [Treatment of brittle fingernails with biotin]. Z Hautkr. 1989;64(1):41-48. 5. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis. 1993;51(4):303-305. 6. Uyttendaele H, Geyer A, Scher RK.Brittle nails: pathogenesis and treatment. J Drugs Dermatol. 2003;2:48-49. 7. Hogan DB, McNair S, Young J, Crilly RG. Nail growth, calcium, and vitamin D. Ann Intern Med. 1984;101:283. 8. Totsi A, Piraccini BM, Cameli N, et al. Calcipotriol ointment in nail psoriasis: a controlled double-blind comparison with betamethasone dipropionate and salicylic acid. Br J Dermatol.1998;139:655-659. 9. Zakeri M, Valikhani M, Mortazavi H, Barzegari M. Topical calcipotriol therapy in nail psoriasis: a study of 24 cases. Dermatol Online J. 2005;11:5. 10. Piraccini BM, Tosti A, Iorizzo M, Misciali C. Pustular psoriasis of the nails: treatment and long-term follow-up of 46 patients. Br J Dermatol. 2001;144:1000-1005. 11. Williams HC, Buffham R, du Vivier A. Successful use of topical vitamin E solution in the treatment of nail changes in yellow nail syndrome. Arch Dermatol. 1991;127:1023-1028. 12. Ayres S Jr, Mihan R. Yellow nail syndrome: response to Vitamin E. Arch Dermatol. 1973;108:267-268. 13. Ridley CM. Pigmentation of fingertips and nails in vitamin B12 deficiency. Br J Dermatol. 1977;97:105-106. 14. Noppakun N, Swasdikul D. Reversible hyperpigmentation of skin and nails with white hair due to vitamin B12 deficiency. Arch Dermatol. 1986;12:896-899. 15. Foti C, Cassano N, Palmieri VO, et al. Transverse leukonychia in severe hypocalcemia. Eur J Dermatol. 2004;14:67-68. 16. Kumar G, Vaidyanathan L, Stead LG. Images in emergency medicine. Koilonychia, or spoon-shaped nails nails, is generally associated with iron-deficiency anemia.Ann Emerg Med. 2007;49(2):243-250. 17. Weismann K. Lines of Beau: possible markers of zinc deficiency. Acta Dermato-Venereol. 1977;57:88-90. 18. Reich H, Opitz K Bertram HP, Fegeler K. Successful zinc treatment of a severe case of acrodermatitis enteropathica. Dtsch Med Wochenschr. 1976;101:1724-1726. 19. Arroyo JF, Cohen ML. Improvement of yellow nail syndrome with oral zinc supplementation. Clin Exp Dermatol. 1993;18:62-64. 20. Longnecker MP, Stampfer MJ, Morris JS, et al. A 1-y trial of the effect of high-selenium bread on selenium concentrations in blood and toenails. Am J Clin Nutr. 1993;57:408-413. 21. Reid ME, Stratton MS, Lillico AJ, et al. A report of high-dose selenium supplementation: response and toxicities. J Trace Elem Med Biol. 2004;18:69-74. 22. Lassus A. Colloidal silicic acid for oral and topical treatment of aged skin, fragile hair and brittle nails in females. J Int Med Res.1993;21(4):209-15. 23. Lassus A. Colloidal silicic acid for the treatment of psoriatic skin lesions, arthropathy and oncyhopathy: A pilot study. J Int Med Res. 1997;25:206-209.
