Your fingernails can say a lot about your health.
Nail beds constantly give rise to nail tissue, and adequate vitamin, mineral, and nutrient intakes help support new nail cells’ growth, formation, and strength.
A change in the appearance, texture, or shape of your nails could indicate nutrient deficiencies.
Here are the 8 essential vitamins and nutrients to keep your nails healthy.
Biotin is a B-complex vitamin known as vitamin B7, coenzyme R, and vitamin H.
It promotes healthy cell growth and aids in the metabolism of protein-building amino acids essential for nail growth.
Biotin-rich foods and supplements may help strengthen your brittle fingernails. A few small studies support biotin supplement use to that effect.
One study in 35 people with brittle fingernails found that 2.5 mg of biotin per day for six weeks to seven months improved symptoms in 63% of participants.
Deficiency in this vitamin is rare, and while there is no recommended dietary allowance for biotin, the adequate intake recommendation for adults has been set at 30 mcg per day.
Biotin is most concentrated in organ meats such as liver but can also be found in egg yolk, dairy products, yeast, salmon, avocado, sweet potato, nuts, seeds, and even cauliflower.
Summary: Biotin deficiency is rare, but consuming biotin through foods or supplements may help strengthen brittle nails and improve their growth.
2. Other B vitamins
Other B vitamins are also essential for nail health.
Vitamin B12 plays a role in iron absorption and the development of red blood cells. Both iron and B12 are necessary for keeping nails strong and healthy.
A deficiency in vitamin B12 can result in entirely blue nails, bluish-black pigments with wavy longitudinal dark streaks, and brownish pigmentation.
Likewise, folate, or vitamin B9, is essential for nail growth and health by contributing to red blood cell formation and the developing of new cells.
A folate deficiency can cause a pigment change in your nails, making them rigid and brittle.
To prevent deficiencies, adults require 2.4 mcg of vitamin B12 and 400 mcg of folate per day, though pregnant women have an increased need.
Folate can be found in dark green vegetables, citrus fruits, beans, peas, lentils, nuts, seeds, and avocados. On the other hand, B12 is primarily found in animal foods, such as meat, poultry, fish, eggs, and dairy, though it can be fortified into other foods and beverages.
Summary: Both vitamin B12 and folate play a role in red blood cell production and oxygen transportation to nail cells. Inadequacies can result in discoloration of your nails.
Iron composes the center of red blood cells, which carry oxygen to your organs and every cell in your body — including your nails.
Without iron, oxygen does not get adequately carried to your cells.
As oxygen is needed for healthy nails, an iron deficiency or anemia can lead to vertical ridges in your nails, or your nails may concave or “spoon”.
Recommended dietary allowances for iron vary considerably depending on age and gender. The recommendation for men is 8 mg per day, while that for women aged 19–50 is 18 mg per day. After women hit age 50 or go through menopause, their iron needs to drop to 8 mg daily.
Your body absorbs the iron in animal foods, such as beef, chicken, fish, and eggs, better than in plant foods like dark green leafy vegetables, peanuts, seeds, beans, and other fortified foods.
However, eating a food rich in vitamin C and a plant-based iron source improves absorption. For example, eating oranges and strawberries alongside a spinach salad with beans and seeds improves iron absorption.
Summary: Iron is needed to provide your cells with adequate oxygen, which, in turn, is necessary for healthy nails. If you have an iron deficiency, the shape and appearance of your nails can be affected.
Magnesium is a mineral involved in over 300 reactions in your body, including protein synthesis, which is required for nail growth.
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Vertical ridges in your nails may be a sign of a magnesium deficiency. Despite the worldwide availability of this mineral, the World Health Organization (WHO) reports that less than 60% of the US population consumes the recommended amount.
The recommended dietary allowance is 400-420 mg and 310–320 mg per day for men and women, respectively.
Whole grains, specifically whole wheat, are a rich source of magnesium. Dark green leafy vegetables and quinoa, almonds, cashews, peanuts, edamame, and black beans are good sources.
Summary: Adequate magnesium intake is crucial to prevent vertical ridges in your nails. This mineral also helps with protein synthesis and the formation of new nails.
Nails are primarily made of a fibrous structural protein called keratin. This is what gives nails their strength and resilience. It also protects your nails from damage or stress.
Interestingly, the keratin you see is dead. Nails are formed by dead cells, which your body sheds as new cells push up from underneath.
Eating enough protein in your diet is essential for boosting keratin production and thus creating strong nails, whereas low protein intake may cause weaker nails.
The recommended dietary allowance for protein is 0.36 grams per pound (0.8 grams per kg) of body weight per day. This equals approximately 55 grams of protein per day for a 150-lb (68-kg) person.
However, the acceptable macronutrient distribution range allows the protein to account for 10–35% of your total daily calories — significantly more than the recommended dietary allowance.
Protein can be found in animal foods like meat, poultry, fish, eggs, and dairy and in plant foods such as soy, legumes, beans, lentils, nuts, seeds, and whole grains.
Summary: Adequate protein intake is needed to produce keratin, which is responsible for keeping your nails strong and resilient.
6. Omega-3 fatty acids
Omega-3 fatty acids can help lubricate and moisturize your nails, giving them a shiny appearance.
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These fatty acids may also reduce inflammation in your nail bed, which nourishes and promotes the health of cells that give rise to your nail plate. A lack of omega-3 fatty acids could contribute to dry and brittle nails.
There is no recommended dietary allowance for omega-3 fatty acids, but the adequate intake is 1.6 grams and 1.1 grams per day for men and women, respectively. The AMDR says that up to 1.6% of total calories can come from omega-3s.
Fatty fish like salmon, trout, mackerel, tuna, and sardines top the charts with omega-3s, but they can also be found in walnuts, soy, eggs, chia seeds, flaxseeds, and fish and flaxseed oil.
Summary: To prevent dry and brittle nails, consume adequate omega-3 fatty acids. They help lubricate your nails, giving them a shiny appearance.
7. Vitamin C
Vitamin C is essential for producing collagen, a protein that gives shape, strength, and integrity to many tissues and is the building block of fingernails, hair, and teeth.
A deficiency in vitamin C can result in brittle nails and slowed nail growth.
Vitamin C is an essential nutrient and cannot be produced by your body. Men require 90 mg and women 75 mg per day.
While citrus fruits, such as oranges, strawberries, and kiwi, are thought to be the best sources of vitamin C, bell peppers, green vegetables, and tomatoes are very high in this nutrient.
Red bell peppers have more than twice the vitamin C of an orange.
Summary: Vitamin C is essential for collagen production, which helps provide strength and integrity to your nails.
Zinc is required for many reactions in your body, including the growth and division of cells.
Nails are made up of a type of cell that grows and divides rapidly. Because of this fast production, a steady supply of zinc is needed to promote the healthy growth of nails.
Inadequate zinc intake can contribute to a degeneration of your nail plate, causing white spots on your nails.
The recommended dietary allowance for zinc is 11 mg and 8 mg daily for men and women.
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Animal proteins like beef, poultry, fish, and eggs are rich sources of zinc. However, soy, chickpeas, black beans, nuts (such as almonds and cashews), and seeds contain it.
Summary: Zinc is required for the healthy growth of your nails. Animal proteins are a great way to consume adequate zinc through your diet, though certain plant foods also pack this mineral.
Supplements vs. food sources
A nutrient-rich diet is likely the best way to achieve strong, shiny, healthy nails.
While many supplements are marketed for strengthening nails, scientific evidence is lacking. To date, biotin supplements are the only type shown to have a possible effect.
However, it’s important to note that deficiencies in certain vitamins, minerals, and nutrients may negatively affect your nail health.
Try to get your vitamins and nutrients from food, but when you can’t, taking a supplement can help you meet your needs and likely improve your nail health.
Summary: Consuming various vitamins, minerals, and nutrients through food is the best way to improve and maintain nail health. Under certain circumstances, a supplement may be beneficial, though scientific research lacks.
While consuming various vitamins, minerals, and nutrients through food contributes to growing and maintaining healthy nails, evidence suggests that supplementing with them may not.
Biotin is the exception, and supplements of this vitamin may help restore brittle nails.
Overall, if you want strong, shiny nails, include a variety of fruits, vegetables, nuts, and seeds in your diet, as well as adequate protein and omega-3 fatty acids.