Are Brittle Nails a Sign of a Vitamin or Mineral Deficiency?

Note: The U.S. Food and Drug Administration (FDA) does not approve supplements for safety or effectiveness. Talk to a healthcare professional about whether a supplement is the right fit for your individual health, and about any potential drug interactions or safety concerns.
“There are many causes of brittle nails, which include too much or too little moisture and chemical damage from nail polish, cleaning agents, or detergents,” says Rahaf Al Bochi, RDN, a Baltimore-based spokesperson for the Academy of Nutrition and Dietetics and the owner of Olive Tree Nutrition. “Most often, the cause of brittle nails is wetting and drying nails over and over, which removes moisture and causes them to be dry and brittle.”
“If a diet lacks foods rich in these nutrients or if there is poor digestion or absorption of nutrients, then a deficiency may occur, and further lab testing would be needed to confirm,” says Al Bochi.
What Your Nails Say About Your Health

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Nutritional Deficiencies That Can Cause Brittle Nails
“Deficiencies in several vitamins or minerals can cause brittle nails,” says Al Bochi.
According to Al Bochi, a lack of one or more of these nutrients might make nails brittle:
- White spots
- Vertical lines or ridges
- Indentations
“Your healthcare provider can run lab testing to assess for deficiencies,” says Al Bochi.
Note that extreme eating habits may contribute to nutritional deficiencies, particularly disordered eating such as anorexia nervosa or fad diets, adds Jamie Rosen Manning, MD, a dermatologist based in New York City.
Can You Reverse Your Brittle Nails by Getting More Nutrients?
It depends.
If your doctor thinks that a nutritional deficiency could be the culprit, they might suggest switching up your diet. “Eat a variety of foods to get the vitamins and minerals your body needs to nourish your body from the inside out,” says Al Bochi.
For example, they might recommend the following foods to get more of these vitamins:
- Iron Beef, poultry, fish, beans, and lentils
- Vitamin C to Help With Iron Absorption Citrus fruits, kiwi, red peppers, strawberries, and tomatoes
- Vitamin B12 and Biotin Beef liver, meats, poultry, fish, clams, oysters, eggs, cheese, milk, nuts, seeds, sweet potatoes, spinach, and broccoli
- Zinc Oysters, meat, fish, poultry, beans, nuts, whole grains, and dairy
- Protein Meat, fish, poultry, nuts, seeds, and legumes
- Magnesium Nuts, seeds, avocados, spinach and other greens, and whole grains
- Folate Spinach, black-eyed peas, and asparagus
- Omega-3 Flaxseed, chia seeds, and salmon
Should I Take Supplements for Stronger Nails?
If a nutrient deficiency is truly the reason for your brittle nails, your doctor might suggest addressing your diet first, says Dr. Manning. But if your doctor gives you the green light to take a supplement as well, there is some research showing that certain kinds are beneficial for brittle nails.
While some studies indicate that biotin supplements strengthen brittle nails, these studies are small and of lower quality. More research is needed to conclusively show a connection between biotin supplements and brittle nails.
“Collagen is made of amino acids that help form keratin, so it makes sense biologically,” says Cristina Del Toro Badessa, MD, a board-certified physician with Artisan, a plastic surgery practice in Atlanta. “I often suggest it as part of a holistic nail health plan, especially since it may also benefit skin and joint health. It’s not a guaranteed fix, but it’s safe, and many of my patients do report stronger nails after a few months.”
If you want to take a supplement, talk to your doctor first.
“In my experience, it’s safe to try a moderate dose of biotin short-term, particularly if we’ve ruled out more serious causes like iron or thyroid issues,” says Dr. Del Toro Badessa. “I also remind patients to let their doctor know if they’re taking it, since high-dose biotin can interfere with lab tests, including thyroid and cardiac markers.”
If you think you could benefit from supplements, we're here to help. Check out our list of the best vitamins for hair, skin, and nails, as recommended by RDs.
Vitamins and supplements are also not evaluated by the U.S. Food and Drug Administration (FDA). So if you do get the green light to take them, ask your doctor if there are any brands in particular they recommend, and follow up as directed.
Other Factors That May Cause Brittle Nails
Outside of nutritional deficiency, there are a number of other reasons why you might have brittle nails, says Al Bochi.
For example:
- Dishwashing may dry out your nails, making them brittle, says Al Bochi. Wear cotton-lined rubber gloves when you do the dishes or when cleaning and using harsh chemicals.
- Nail polish remover can wear down your nails, making them more brittle over time. Choose products that don’t contain acetone to prevent this. Certain lacquers and moisturizers can strengthen brittle nails.
- Brittle nails may be a sign of a fungal infection or an underlying health issue such as psoriasis, a thyroid disorder, or Raynaud’s syndrome (where you have less blood flow to your nail beds).
- Brittle nails may be a side effect of a medical treatment like chemotherapy.
- Even the climate you live in can make a difference. “Hot, dry climates, or even cold, dry air indoors, can draw moisture out of the nails, making them more brittle,” says Del Toro Badessa, adding that nails contain water, and when moisture drops, they lose flexibility and are more prone to splitting or cracking.
“I tell patients to treat their nails like they treat their skin: Nourish them from the inside, protect them from the outside,” says Del Toro Badessa.
The Takeaway
- Brittle nails that chip easily are usually a sign of aging, external damage, or certain medical treatments.
- In rare cases, brittle nails could be a sign of a nutritional deficiency.
- Lack of iron, B vitamins like biotin or B12, zinc, protein, or magnesium in your diet may contribute to brittle nails.
- Healthy, well-rounded meals will strengthen your nails. If you still have a nutritional deficiency, your doctor may recommend dietary supplements.
- Brittle Nails. National Library of Medicine. June 7, 2023.
- What Causes Brittle Nails and How To Treat Them. Cleveland Clinic. November 16, 2022.
- Nett K. What You Eat Promotes Radiant Hair, Skin and Nails Naturally. Mayo Clinic. May 26, 2022.
- Biotin Fact Sheet for Consumers. National Institutes of Health. December 8, 2017.
- Chessa MA et al. Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review. Dermatology and Therapy. November 20, 2019.
- What Causes Brittle Nails and How To Treat Them. Cleveland Clinic. November 16, 2022.
- Ridges in Nails. Cleveland Clinic. November 16, 2022.
- Grover C et al. Nail changes associated with pigmentary disorders. Pigment International. May-August 2021.
- 52 Foods High in Iron. Cleveland Clinic. March 15, 2023.
- Vitamin C. National Institutes of Health. March 26, 2021.
- Vitamin B12. National Institutes of Health. December 15, 2023.
- Biotin. National Institutes of Health. January 15, 2021.
- Zinc. National Institutes of Health. October 4, 2022.
- High-protein foods: The best protein sources to include in a healthy diet. Harvard Medical School. December 1, 2023.
- 25 Magnesium-Rich Foods You Should Be Eating. Cleveland Clinic. March 17, 2023.
- Folate. National Institutes of Health. November 30, 2022.
- Omega-3 Fatty Acids. National Institutes of Health. December 17, 2024.
- Is Biotin as Good as Advertised for Your Hair Loss? Cleveland Clinic. October 26, 2022.
- Hochman LG et al. Brittle nails: response to daily biotin supplementation. Cutis. April 1993.
- Chessa MA et al. Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review. Dermatology and Therapy. November 20, 2019.
- Hexsel D et al. Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails. Journal of Cosmetic Dermatology. 2017.
- Collagen. Cleveland Clinic. May 23, 2022.
- Bistas KG et al. Biotin. StatPearls. July 3, 2023.
- Mixing Medications and Dietary Supplements Can Endanger Your Health. U.S. Food and Drug Administration. June 2, 2022.
- FDA 101: Dietary Supplements. U.S. Food and Drug Administration. June 2, 2022.
- Yes, You Can Take Too Many Vitamins. Cleveland Clinic. May 13, 2024.
- Biotin may throw off lab test results. Harvard Medical School. December 1, 2018.
- Fingernails: Do's and don'ts for healthy nails. Mayo Clinic. November 22, 2024.

Jacquelyn Dosal, MD
Medical Reviewer
Jacquelyn Dosal, MD, is a board-certified dermatologist at Skin Associates of South Florida in Coral Gables. She practices general, medical, cosmetic, and surgical dermatology.
Dr. Dosal provides compassionate care to all her patients, listening to their concerns and creating a treatment plan with each patient's priorities and real life in mind.
She is a member of the voluntary faculty at the University of Miami.
