Vitamin D is an essential nutrient that plays a role in many of the body's functions. A vitamin D deficiency may cause numerous problems, including hair loss.
There is some evidence that having a vitamin D deficiency does cause hair loss and other hair problems. Vitamin D stimulates hair follicles to grow, and so when the body does not have enough, the hair may be affected.
A vitamin D deficiency may also be linked to alopecia areata, an autoimmune condition that causes patchy hair loss.
Research shows that people with alopecia areata have much lower levels of vitamin D than people who do not have alopecia.
Vitamin D deficiency can also play a role in hair loss in people without alopecia. Other research shows that women who have other forms of hair loss also had lower levels of vitamin D.
Vitamin D affects the health of many parts of the body, including the skin and hair.
Vitamin D plays a role in the creation of new hair follicles. Hair follicles are the tiny pores from which new hairs grow. New follicles may help hair maintain thickness and prevent existing hair from falling out prematurely.
Because of this link, getting adequate amounts of vitamin D can support hair growth and regrowth.
People with a vitamin D deficiency may have no symptoms, or their symptoms may be nonspecific and change over time.
Symptoms of a vitamin D deficiency include:
- changes in mood, including depression or anxiety
- frequent fractures
- slow wound-healing
- loss of bone density
- muscle weakness
- new or worsening high blood pressure
- constant fatigue
- chronic pain
- decreased endurance
A lack of sunlight or not eating enough foods rich in vitamin D are the most common causes of a vitamin D deficiency.
People with an underlying medical condition will experience symptoms of the primary cause and symptoms of a vitamin D deficiency, as well.
Certain medications may also cause the body to break down vitamin D before it can be used. Medications that may cause a vitamin D deficiency include:
- medications for HIV
If a medication is causing a vitamin D deficiency or hair loss, a person should speak to their doctor about alternatives.
Research suggests that when a person lacks Vitamin D, the most effective treatment is for them to take vitamin D supplements.
Vitamin D supplements should be taken with meals, particularly ones with plenty of healthful fats. Fat helps the vitamin D to be absorbed into the body.
Good sources of dietary fat include:
- chia seeds
- some fish, include salmon, trout, and sardines
Supplements come in a variety of forms. Some may be taken daily, once a week, or once a month. When treating low vitamin D levels, a doctor will do a blood test every few months to see if a person's levels are increasing.
The Endocrine Society recommend that adults between the ages of 19 and 55 receive 600 IU of vitamin D daily. The unit "IU" stands for international unit, which describes how potent a vitamin or supplement is, rather than its mass.
The Endocrine Society recommend that adults over 55 years old receive between 600 and 800 IU per day of vitamin D. Finally, they recommended between 400 and 600 IU per day of vitamin D for children.
In cases where an underlying condition is causing the deficiency, the condition will need to be treated.
Both Crohn's and celiac disease can cause a vitamin D deficiency. These diseases partially or fully block the absorption of vitamin D from food.
If medications are the cause, a person may need to discuss alternatives with their doctor.
For mild deficiencies, increasing the amount of time spent in the sun can also help. However, it is important to wear sunscreen and avoid prolonged exposure to reduce the risk of skin damage.
A person's first defense against hair loss caused by a vitamin D deficiency is spending 15 to 20 minutes outside per day and eating foods that are rich in vitamin D.
A person may also want to add a vitamin D supplement to their routine to support their vitamin D intake goals.
Brittle or sparse hair requires gentle treatment, so anyone experiencing hair loss can prevent further breakage by:
- not pulling the hair when brushing
- avoiding ponytails and other tight hairstyles
- using a gentle and natural conditioner
- putting long hair in a loose braid before bed to prevent tangling
Vitamin D affects many aspects of a person's health and well-being, including hair growth. Having a vitamin D deficiency makes people more likely to experience hair loss and many other problems.
People concerned about vitamin D deficiency-related hair loss should consult a doctor who will likely suggest supplements, dietary changes, and spending more time outdoors to help combat the deficiency.