What Your Fingernails Say About Your Health

Your fingernails can provide valuable insights into your health. Nail issues, such as breakage, abnormal shape, and discoloration, can arise from factors including nutrient deficiencies¹, poor circulation, chronic diseases, and hormonal imbalances.

Your nails are actually a helpful window into your body’s nutrient status, internal organ function, and even chronic conditions.

In this article, we'll explore how different fingernail issues can signal specific health concerns—including a lack of nutrients like zinc or vitamin B12, for example—and what you can do to improve your nail health (and, therefore, your general well-being) naturally.

The Connection Between Your Nails and Nutrient Status

Nails are primarily made of keratin², a type of tough, protective protein that is also found in your hair and the outer layer of your skin. As new keratin cells grow, older cells are pushed forward, hardened, and compacted to form the visible nail plate, which is what you see as your fingernail.

The nail structure itself is composed of several parts³, including the following:

Nail plate, the hard part of the nail
Nail bed, the skin beneath the nail plate
Cuticle, the protective layer of skin at the base of the nail
Nail matrix, where new nail cells are produced
Lunula, the half-moon-shaped white area at the base of the nail

Aside from keratin, nails also contain small amounts of other nutrients, including calcium, lipids (fats), and sulfur compounds, which contribute to their strength, flexibility, and resilience.

Vitamins for Nail Health

To grow and maintain healthy fingernails, your body requires the following vitamins for nail health:

Protein: Nails are primarily made of a protein called keratin. Ensuring sufficient protein intake through foods like lean meats, fish, eggs, nuts, seeds, and legumes is crucial for strong nails.

Biotin (Vitamin B7): Biotin supports healthy cell growth and aids in the metabolism of amino acids, which are essential for nail growth. Foods rich in biotin include eggs, nuts, seeds, salmon, and sweet potatoes.

Zinc: Zinc contributes to the maintenance and growth of cells and supports immune function. You can find zinc in foods such as oysters, beef, pumpkin seeds, lentils, and chickpeas.

Iron: Iron deficiency can lead to brittle nails. Good sources include red meat, poultry, seafood, beans, lentils, spinach, and fortified cereals.

Vitamin E: This antioxidant helps maintain healthy nail beds by improving circulation and preventing cracked or dry cuticles. Nuts, seeds, avocados, and vegetable oils are rich in vitamin E.

Omega-3 Fatty Acids: These promote nail moisture, making nails less likely to become brittle. Omega-3s are found in fatty fish (like salmon), walnuts, flaxseeds, and chia seeds. You can also include a quality fish oil, like Omega Plus to your supplement routine.

Calcium: Essential for bone and nail strength. Dairy products, fortified plant-based milk, leafy greens, and almonds are good sources of calcium.

Vitamin C: This vitamin is important for collagen production, which is a key part of nail health. Citrus fruits, strawberries, bell peppers, and broccoli are high in vitamin C.

Magnesium: Important for protein synthesis and structural support of the nails. Whole grains, nuts, seeds, dark chocolate, and leafy greens provide magnesium.

B Vitamins (Riboflavin, Folate, and B12): These vitamins support nail growth by improving red blood cell production and circulation. Found in lean meats, eggs, dairy products, green vegetables, and fortified cereals.

You can see why proper nutrition and nutrient absorption are all important for maintaining the strength, appearance, and integrity of your nails. When it comes to nail health and vitamins, including Prenatal Plus and Omega Plus can provide your body with the key nutrients.

Causes of Poor Nail Health

What does a healthy nail look like? They are smooth and uniform⁴ in terms of texture and color. On the other hand, changes in your nails' appearance, along with the “glow” and thickness of your skin and hair, can signal various underlying nutritional deficiencies or health conditions.

Common causes of fingernail issues⁵ include:

Nutrient deficiencies, for example, zinc, biotin, iron, and vitamin B12
Dehydration, which causes a lack of moisture and nails to become brittle and cracked (same goes for your skin and hair!)
Chronic conditions, such as diabetes, lung disease, pulmonary disease, inflammatory bowel disease, and anemia
Hormonal imbalances, especially thyroid disorders like hypothyroidism (an underactive or “sluggish” thyroid, which can also cause hair loss)
Poor circulation, which can reduce the delivery of nutrients to the nail bed, leading to slower growth and discoloration
Trauma to the nail bed or reactions to certain products⁶
Skin-related issues such as psoriasis or dermatitis
Poor circulation
Genetics, which can contribute to autoimmune conditions and other issues that impact the nails
Biting or picking your nails and cuticles⁷

What Fingernails Tell You About Your Health

Here's more about potential reasons your fingernails may be weak, brittle, or discolored and what you can do about it:

1. Soft or Thin Nails

Thin nails that break easily can be a sign of low protein intake, biotin deficiency⁸, or hormonal imbalances like low estrogen. You need enough protein and biotin for your body to make keratin and keep your nails strong; therefore, look at your diet first.

Also consider your estrogen levels. Estrogen supports nail growth by enhancing blood circulation and collagen production, which helps maintain strong and healthy nails. Lower estrogen levels, such as during menopause, can lead to slower nail growth and increased brittleness.

If you’ve been receiving gel or acrylic nails and recently had them removed, this may be the cause of your thin nails. The solution is to allow them time to grow out and to ensure you have adequate nutrition during the process.

Possible Causes: Low protein, biotin deficiency, hormonal imbalances, gel or acrylic nails.

Solutions:

Protein: Ensure you’re getting enough protein from sources like chicken, fish, legumes, and eggs. Aim to increase your daily protein intake up to about 100 grams per day, which also supports muscle and bone health, especially as you age.
Biotin: Try a biotin supplement or include more biotin-rich foods like eggs, nuts, and seeds in your diet.
Nutrient-rich diet: Aside from protein and biotin, vitamins C, A, E, and D, along with iron, healthy fats like omega-s, and antioxidants all contribute to nail health⁹.
To obtain these nutrients, emphasize these skin, hair, and nail-supporting foods¹⁰:
- Eggs
- Leafy greens, carrots. peppers, and other veggies
- Almonds, walnuts, and other nuts
- Flax, chia, hemp, pumpkin, and other seeds
- Fish like salmon and shellfish like oysters
- Grass-fed meats
- Poultry
- Dairy products
- Collagen protein powder
- Berries, citrus fruits, kiwi, mango, and other fresh fruits

2. Brittle Nails and Vitamin Deficiency

Brittle or cracked nails that break easily can be a sign of dehydration, vitamin deficiencies, or thyroid imbalance.

It can also be due to reactions to certain products your hands touch that cause irritation and damage, such as nail hardeners, polishes, or adhesives, or due to a fungal infection¹¹ (especially if the nail starts splitting or lifting up from the nail bed).

Possible Causes: Low biotin, iron or zinc deficiency, hypothyroidism, lack of moisture, reactions to harsh products.

Solutions:

Biotin: Take a biotin supplement or consume foods like eggs, almonds, and sweet potatoes.
Iron: Increase iron intake through diet or supplements like Prenatal Plus, which is rich in absorbable iron and other essential nutrients for nail and hair health, including B vitamins.
Hydration: Make sure to drink enough water throughout the day and use a hydrating hand cream to keep nails moisturized.
Stop putting products on your nails to let them heal.

3. Vertical Ridges on Nails

Vertical ridges running from the cuticle to the tip of the nail are one of the most common nail changes and are usually harmless. However, deeper or more pronounced ridges could indicate an iron deficiency or a lack of protein¹².

Possible Causes: Vertical ridges are often related to aging, but they can also be linked to nutritional deficiencies, including a lack of iron or vitamin B12.

Solutions:

Iron: Consider increasing iron intake with iron-rich foods like spinach, lentils, and red meat, or try a supplement like Prenatal Plus.
B12: Incorporate B12-rich foods in your diet, such as eggs, fish, and dairy, or consider taking a high-quality B12 supplement if levels are low. You'll find B12 in my B Active Plus formula, as well as many multivitamins (including my Prenatal Plus).

4. White Spots in the Nails (Leukonychia)

White spots in the nails, also called leukonychia, can be caused by damage to the nail plate, but they may also signal a zinc or calcium deficiency.

Possible Causes: Zinc deficiency, minor nail trauma, calcium deficiency.

Solutions:

Zinc: Add more zinc-rich foods to your diet, such as chickpeas, pumpkin seeds, and cashews, or try a zinc supplement, which can include a quality multivitamin (like my Women's Twice Daily capsules).
Calcium: Include dairy, leafy greens, and almonds in your diet, or try a calcium supplement if your diet is lacking. Pair calcium with vitamin D to help with calcium absorption and provide other benefits, including helping with immune function and hormone production.

5. No Half Moons (Lunula)

The absence or reduction of the visible white half-moon shape (lunula) at the base of the nails can indicate low thyroid function or B12 deficiency.

Possible Causes: Thyroid disorders, B12 deficiency, circulatory issues.

Solutions:

Thyroid Support: Ensure adequate iodine intake with foods like seaweed, seafood, and iodized salt, or consider a thyroid-supporting supplement.
B12: Add B12-rich foods such as liver, beef, and fortified cereals, or take a B12 supplement.

6. Clubbing of Nails

Clubbing refers to the rounding of the fingertips and nails, often accompanied by thickening. This can potentially be a sign of lung, heart, or liver disease¹³ since these conditions impact how much oxygen and nutrients can reach the fingernails.

Possible Causes: Chronic low oxygen levels, lung disease, heart disease, liver cirrhosis.

Solutions:

While addressing nail clubbing usually involves treating the underlying health condition, you can support lung health with anti-inflammatory foods like leafy greens, turmeric, ginger, and garlic.
Discuss testing and any concerns with your healthcare provider to address the root cause.

7. Dark Lines Under the Nails

A dark line or streak beneath the nail can be caused by trauma or a vitamin deficiency. According to the American Academy of Dermatology Association¹⁴, dark lines in the nails can also signal a more serious health condition, such as melanoma, a dangerous type of skin cancer that develops in melanocytes, the cells that produce melanin and color the skin.

Having a dark line on toenail is known as melanonychia. It appears as a dark brown or black line that extends from one end of the nail bed to the tip. If you have a dark complexion, this may be normal.

Possible Causes: Vitamin B12 deficiency, trauma, melanoma.

Solutions:

B12: Increase intake of B12 through foods or supplements.
If the dark line persists, consult a dermatologist to rule out any serious conditions and discuss testing for melanoma.

8. Peeling Skin Around Nails

Peeling skin around your nails can be related to a lack of moisture, but it can also indicate a deficiency in essential fatty acids or vitamin C or an infection¹⁵.

Possible Causes: Dry skin, vitamin C deficiency, lack of essential fatty acids, infection.

Solutions:

Vitamin C: Include more citrus fruits, strawberries, and bell peppers in your diet, or take a vitamin C supplement.
Healthy fats: Add foods like avocados, nuts, and olive oil to your diet to increase essential fatty acid intake.
Hydration: Stay well-hydrated by drinking enough water and using hand creams that contain hydrating ingredients like shea butter or coconut oil.
Talk to your provider if the nail also becomes red and swollen.

9. Yellow Nails

Yellow nails can be caused by smoking, fungal infections, or an underlying lung condition. They can also indicate diabetes or thyroid disease.

Possible Causes: Smoking, fungal infections, diabetes, hypothyroidism.

Solutions:

Fungal treatment: Use antifungal treatments if needed, or try natural antifungals like tea tree oil.
Blood sugar support: Focus on a balanced, low-glycemic diet that contains plenty of fiber, protein, and healthy fats.
Talk to your provider about testing your liver health and potentially treating any type of fungal infection you may have.

10. Spoon-Shaped Nails (Koilonychia)

Spoon-shaped nails that curve outward can indicate iron-deficiency anemia or other issues like hypothyroidism.

Possible Causes: Iron deficiency anemia, hypothyroidism.

Solutions:

Iron: Increase iron intake through diet or with iron supplements.
Thyroid Support: Consider iodine-rich foods or a Thyroid Support supplement.

11. Horizontal Ridges (Beau’s Lines)

Horizontal ridges, known as Beau’s lines, can point to a sudden disruption in the nail growth process that's usually due to illness, stress, or trauma¹⁶.

Possible Causes: Major illness, stress, malnutrition, uncontrolled diabetes, some medications, lack of nutrients.

Solutions:

Addressing the underlying cause, whether it be managing stress, boosting nutrition, or improving blood sugar control, is essential.
Focus on a balanced diet with plenty of protein, healthy fats, and vegetables.
Talk to your healthcare provider about testing and management, depending on your health history.

When to See a Doctor

If you suddenly notice that your nails are changing shape, color, or density, or are falling off or not growing, consider getting your provider's opinion.

If you develop signs of infection around your nails, such as redness and swelling that doesn't go away within several days, visit your provider for an evaluation and potentially medication to treat a fungal or bacterial infection.

Key Takeaways on Improving Nail Health

By taking a closer look at your nails, you can gain valuable insights into your body’s overall nutrient intake and health. Remember, if you notice sudden or dramatic changes in your nails, it’s best to consult a healthcare provider to explore possible underlying issues.

Here's a recap of how to take care of your nails:

Eat a balanced diet: Include plenty of fruits, vegetables, lean proteins, and healthy fats to supply your body with the nutrients needed for strong nails.
Stay hydrated: Drinking enough water can prevent nails from becoming dry and brittle.
Consider supplements: Supplements like Prenatal Plus, Zinc Support, Biotin Support, and Immune C can support overall nail health.
Address underlying conditions: Chronic diseases, nutrient deficiencies, and hormonal imbalances should be addressed to improve nail health.
Moisturize regularly: Keep nails and surrounding skin well-moisturized to prevent peeling and cracking.

References

About The Author

Dr. Jolene Brighten

Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.