6 Signs of Vitamin Deficiencies That Can Show Up in Your Nails (With Pictures)

They say that eyes are the windows to the soul. But your nails can be windows to your health. Changes in your fingernails and toenails can sometimes be early signs of medical conditions, infections, and even vitamin deficiencies. 

Here are six signs of vitamin deficiency in nails to know about. 

What kind of nail changes can be a sign of a vitamin deficiency?

Vitamin deficiencies can cause many different nail changes, including changes in nail color, shape, and texture. Some of the nutrients most commonly associated with nail changes include:

• Iron

• Zinc

• Vitamin B12

• Biotin (B7)

• Calcium

• Protein

It’s important to remember that nail changes can have causes other than vitamin deficiencies. Infections, psoriasis, and even menopause are examples of conditions that can affect the appearance of your nails. That’s why it’s a good idea to get medical care if you notice changes affecting several fingernails or toenails at the same time. 

Here are some of the more common ways vitamin deficiencies can affect your nails. 

1. Nail color changes

Healthy nails have a range of colors, depending on a person’s skin tone and the number of pigment-producing cells (melanocytes) in the nail matrix. Blood vessels underneath the nail bed also lend a range of pinkish to reddish undertones. But certain vitamin deficiencies can affect your nail color.

Iron deficiency can lead to anemia, which can make your nails look more pale than their usual hue. Meanwhile, a vitamin B12 deficiency can sometimes cause nails to appear darker than usual or develop a blue-black discoloration. 

2. Horizontal grooves

Horizontal grooves or depressions that run all the way across your nails can be a sign of vitamin deficiency. This is especially true if you have lines across several fingernails. These depressions are called Beau’s lines. They can be a sign of severe zinc deficiency.

Beau’s lines can be caused by medical conditions and some medications too. But if you have a Beau’s line on only one nail, it was likely caused by an injury, not a medical condition or vitamin deficiency.

3. Vertical ridges

Vertical (or longitudinal) ridges are raised lines that run from the cuticle to the tip of the nail. A single vertical ridge usually happens from minor trauma to the nail or just from getting older. But when multiple nails develop prominent vertical ridges, it can be a sign of an underlying medical condition (like lupus). It can also be due to a nutritional deficiency in: 

• Protein

• Iron

• Folic acid (B9)

• Vitamin B12

4. White horizontal lines

Most white spots on nails aren’t a cause for concern. But white lines that run all the way across your nails can be a sign of a vitamin deficiency, especially if you have multiple lines on several nails. Low calcium and zinc levels can both cause white horizontal lines to form on your nails. These lines are called transverse leukonychia. 

5. Brittle, cracked nails

Brittle nails that break or crack easily can be a sign of a vitamin deficiency. 

Low iron, biotin, and calcium levels can weaken nails and make them softer. Soft, weak nails can crack and break more easily. They’re also drier and may peel or split at the edges. Keep in mind that frequent handwashing and harsh chemicals can also contribute to brittle nails. 

6. Spoon-shaped nails

Nails that are flatter than usual can have a spoon-shaped appearance. This is called koilonychia, and it’s a sign of a vitamin deficiency. Low iron and vitamin C levels can cause nails to develop a spoon-shaped appearance. 

How long does it take for a vitamin deficiency to affect your nails?

It takes time for a vitamin deficiency to affect your nails’ appearance. Your fingernails grow about 3 mm per month, while your toenails grow only about 1 mm per month. 

That means if you develop a severe vitamin deficiency today, it may be a month or two before your fingernails have grown enough for you to notice the difference. It may take even longer for you to see a difference in your toenails. 

How can you tell if your nail changes are from a vitamin deficiency or something else?

Nail changes can be caused by many things like:

• Vitamin and other nutrition deficiencies

• Medical conditions

• Medications

• Injuries

• Infections

It may be difficult to tell if your nail changes are from a vitamin deficiency or another cause. That’s why it’s important to get care if you notice nail changes on most of your nails. 

You’re more likely to have a medical condition or vitamin deficiency if you see changes on both your fingernails and your toenails — and not just one or the other. Medical conditions and nutritional deficiencies also tend to affect multiple nails at the same time. If you notice changes in only one or two nails, an injury or infection is more likely to be the cause. 

Your healthcare team can examine your nails and order tests to figure out what’s causing the changes. 

How long does it take for nail changes to go away once you treat a vitamin deficiency?

Vitamin supplements can correct vitamin deficiencies and help you recover. But vitamin supplements won’t make your nail changes go away. Instead, they make your nails grow back healthy, strong, and with their usual appearance. Your nails won’t recover their normal appearance until they fully grow back. 

As mentioned above, your nails only grow 3 mm a month on average. So it’ll take several months for your nails to look like they used to. Toenails grow even more slowly, so they may take longer to improve. 

Recommended treatments to improve nail health

The best treatment for nail changes depends on the underlying cause. If a vitamin or mineral deficiency is responsible, correcting the deficiency can help your nails grow back stronger and healthier. 

Other ways to support healthy nails include:

• Eating a balanced diet of whole foods

• Moisturizing your hands and cuticles

• Wearing gloves when using cleaning products or chemicals

• Avoiding excessive nail trauma

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Written by:

Jennifer Sample, MD

After a fellowship, Dr. Sample worked as the medical director at the University of Kansas Hospital Poison Center (The University Of Kansas Health System Poison Control Center), which served the state of Kansas for poison exposures. In 2007, she returned to Children’s Mercy Hospital in Kansas City, Missouri, as a consultant in clinical pharmacology and medical toxicology.

Edited by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. A pulmonologist and hospitalist, she practiced and taught clinical medicine at hospitals in London for a decade before entering a career in health education and technology.

Reviewed by:

Maria Robinson, MD, MBA

Maria Robinson, MD, MBA, is a board-certified dermatologist and dermatopathologist who has practiced dermatology and dermatopathology for over 10 years across private practice, academic, and telehealth settings. She is a fellow of the American Academy of Dermatology and the American Society of Dermatopathology.

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