Diet impacts lots of areas of health, including hair health. So, if you’re experiencing thinning hair, you might ask yourself which vitamin deficiency causes hair loss. Interestingly, hair loss isn’t typically caused by vitamin deficiency, although having too much of certain vitamins can contribute to thinning hair.1 Hair loss can also be caused by a lack of protein or iron in your diet.
Continue reading to learn more about which vitamin deficiency causes hair loss, hair loss causes, and how to stop hair loss.
How Vitamin Deficiency Causes Hair Loss
The vitamins and minerals that you consume play a role in the health of your hair follicles and hair growth cycle. However, the exact impact of vitamin intake on hair loss is very complex, and it hasn’t been well-studied.2
Here’s what is known about vitamin deficiency, nutrient intake, and hair loss:1
- Vitamin deficiencies do not typically cause hair loss.
- Getting too many specific vitamins, including vitamin A, can cause hair loss.
- Too little iron and protein can contribute to thinning hair.
- Rapid weight loss (which may overlap with vitamin deficiencies) can cause hair loss.
The research around vitamin intake and hair loss is limited. Researchers have called for more double-blind placebo studies to examine the role of vitamin and mineral intake on hair loss.2
Vitamin Deficiencies That May Contribute to Thinning Hair and Hair Loss
Unfortunately, there aren’t many clear-cut answers when it comes to which vitamin deficiencies cause hair loss. However, this article will cover what we do know about vitamin deficiencies and hair loss, as well as what nutrient intakes can impact your hair.
B Vitamins, Biotin, and Folic Acid
B vitamins play a role in lots of bodily functions, including cell division. Biotin is a type of B vitamin (B7) that helps the body convert food into energy and manage cell communication.
Hair loss and hair shedding can be a symptom of biotin deficiency.3 If you have a deficiency, taking biotin can help stop hair loss.2
But if you don’t have a confirmed biotin deficiency, taking biotin supplements won’t help with hair loss.2 That’s surprising to many people since many companies sell shampoos and other products with biotin, claiming that they’ll improve hair health.
Vitamin D
Vitamin D is best known for keeping your bones strong. Some people with vitamin D deficiency develop hair loss, usually associated with rickets. For people with a vitamin D deficiency, supplementing might help with hair loss.2
In addition, studies have shown a connection between vitamin D deficiencies and autoimmune conditions, including alopecia, a condition that causes hair loss. Supplementing with vitamin D until you’re no longer deficient in vitamin D can help with outcomes and treatments for alopecia.2
Iron
Iron is important for having healthy red blood cells, which carry oxygen throughout your body. If you don’t get enough iron from your diet, you can develop anemia, or a low red blood cell count, which is a cause of hair loss.4
When experiencing hair loss, ask your healthcare provider to screen you for low iron levels and supplement if needed.2
Vitamin C
Vitamin C may be associated with immunity, rather than hair loss, but it’s critical to make sure you’re getting enough of it, especially if you have hair loss associated with low iron levels.2 If you have hair loss associated with iron deficiency, try to get enough vitamin C though citrus foods, potatoes, peppers and other foods packed with this nutrient.
Zinc
Zinc is another trace mineral that supports healthy cell function. Zinc deficiency is rare, but it’s associated with alopecia. However, the research on whether correcting the zinc deficiency can help with symptoms of alopecia, including hair loss, is mixed.2
Vitamin E
Vitamin E helps support your immune system and other bodily functions. There’s little data on vitamin E and hair loss.2
Magnesium
Magnesium is a chemical element that supports brain health. Hair loss is not a typical symptom of magnesium deficiency, but some research shows that supplementing with magnesium can help with hair loss in women with polycystic ovary syndrome (PCOS).5
Can Too Many Vitamins Cause Hair Loss?
Sometimes, hair loss can be caused by getting too much of a certain vitamin or mineral. Here are two that can contribute to hair loss.
Vitamin A
Vitamin A contributes to cellular growth. That might sound positive for your hair, but consuming too much vitamin A can actually cause hair loss.1
How much vitamin A is too much? Most adults shouldn’t consume more than 10,000 international units (IUs) of vitamin A daily. That’s much more than you’d get in a typical diet. If you’re supplementing with vitamin A and notice hair loss, talk with a healthcare provider.2
Selenium
Selenium is a mineral that your body needs in small (trace) amounts. Some research shows that selenium can help with hair loss, including among people who are getting chemotherapy. However, having too much selenium can also cause hair loss. Never take more than 400 IUs of selenium each day.2
Summary
Vitamin deficiencies don’t typically cause hair loss. However, not getting enough iron and developing anemia can cause hair loss. Thinning hair can also be caused by having too much vitamin A. Unless you have a deficiency in a certain vitamin, supplementing with vitamins likely won’t do much for hair loss.
However, hair loss has many causes, including hormonal changes, stress, and infection. If you’re experiencing hair loss, talk with your healthcare provider, who can help you address the causes of hair loss and develop a treatment plan that will work for you.