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Vitamin D Deficiency and Hair Loss: Everything You Need to Know

By Neha Kashyap
Reviewed by Jennifer T. Haley, MD, FAAD on November 18, 2020
Here’s how being low on vitamin D could be causing your hair loss.

Hair loss, also known as alopecia, can occur for several reasons, including hormones, genetics, life stress, and medication. Hair loss can sometimes signal a vitamin deficiency, including low vitamin D levels. Here’s more on how vitamin D could affect hair loss and what to do about it.

Can Vitamin D Deficiency Cause Hair Loss?

Vitamin D is metabolized in the skin by keratinocytes. These are skin cells that process keratin, a protein in hair, nails, and skin. When the body doesn’t have enough vitamin D, keratinocytes in hair follicles have trouble regulating hair growth and shedding.

“There is a link between vitamin D deficiency and alopecia, and it is often one of the common causes of thinning hair or hair loss in men or women,” Arielle Levitan, MD, an internal medicine physician in Chicago, tells WebMD Connect to Care. 

A 2017 review in the International Journal of Molecular Sciences found that low vitamin D levels have been linked to: 

A 2019 study in the Indian Dermatology Online Journal found vitamin D deficiencies could worsen hair loss over time. And a 2016 study from the International Journal of Trichology found that among younger people with hair loss, women showed greater vitamin D deficiency.

Is Vitamin D Deficiency Hair Loss Reversible?

Vitamin D supplements could help if a vitamin D deficiency is contributing to your hair loss. Vitamin D can come in a pill, or it can be applied to the skin through creams like calcipotriol, a psoriasis drug that has shown promise in treating hair loss.

“Supplementing vitamin D can often be helpful since most people are deficient—along with other key nutrients, typically iron, vitamin C, and biotin—in restoring hair loss. It certainly helps thicken existing hair,” Levitan says. “The amount to take varies on the individual's needs, based on who they are, sun exposure, and other medical problems.”

Getting 10 to 30 minutes of sun exposure is a way to get vitamin D, but this could raise skin cancer risks. The amount of sun needed to form Vitamin D will vary depending on your skin type, how much skin is exposed, and where you live. According to Levitan, getting between 800 and 2,000 IU—or 20 to 50 micrograms—of vitamin D daily is usually enough, and “too much can cause toxicity.” Some people require 5,000 IU daily to maintain optimum blood levels and Vitamin D should be taken in the morning with Magnesium for maximum bioavailability.

When it comes to alopecia from autoimmune conditions, or diseases where the body attacks its own hair follicles, it’s best to see a doctor. Treatments for alopecia areata, for example, can include steroid injections and creams, according to the National Alopecia Areata Foundation. While research has linked low vitamin D levels to alopecia areata, the exact mechanism is not yet understood, according to a 2019 review in the American Journal of Translational Research.

Get Help Now

Don’t wait. The sooner you address the symptoms of hair loss, the more likely you are to prevent irreversible damage. Speak to a medical professional today to begin your journey to a fuller head of hair.