Vitamin D has many different effects in the body. The most well-known are its effects on bone health, as severe vitamin D deficiency can lead to rickets, a disease in which bone growth is impaired.
But the vitamin has many other effects in the body: A deficiency can affect hair growth.
When does hair loss occur?
Hair goes through certain growth phases that last different lengths of time. So some hair loss is normal. According to the medical encyclopedia MSD Manual, up to 50 to 100 hairs fall out every day.
Hair loss is diagnosed when more than 100 hairs fall out per day over a long period of time, which can indicate disruptions in the hair growth cycle. However, the amount is very individual: for people with particularly thick hair, a daily loss of more than 100 hairs can be normal, even without medical reasons.
As the Cochrane research network reports, the “most common type of hair loss in women (…) is FPHL, also known as androgenetic alopecia (congenital hair loss).” In English, the type is called “female pattern hair loss,” hence the abbreviation FPHL. Hereditary hair loss is also most common in men, but they develop bald spots, while women’s hair becomes increasingly thinner.
The role of vitamin D in hair loss
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hair growth: Vitamin D plays a crucial role in the hair cycle. It helps stimulate new hair follicles and maintain existing ones. This is essential for hair growth and regeneration.
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Hair follicle cycle: According to a scientific review published in International Journal of Molecular Sciences Studies have also shown that a lack of vitamin D can lead to disruptions in the hair follicle cycle, leading to increased hair loss and hair thinning.
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Vitamin D Deficiency: In 2020, researchers at the College of Medicine in Iraq studied 190 women to test the effects on vitamin D. According to the study, women with FPHL have significantly lower average vitamin D levels compared to the control group. 86.1 percent of women with FPHL had vitamin D deficiency, compared to 36.9 percent in the control group.
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Taking Vitamin D: An article published in an issue of the International Society of Hair Restoration Surgery (ISHRS) describes some case studies with men that show that vitamin D supplementation could lead to forehead hair regeneration. The vitamin D level after vitamin D therapy was 50.6 ng/ml, which the doctor and metabolism expert Helena Orfanos-Boeckel sees in her guide “Nutritional Therapy” as the lower limit of the therapeutic target range.
Should you take vitamin D if you have hair loss?
First of all, it is important to check whether there is pathological hair loss. For this purpose, the dermatologist often carries out a hair washing test in which hair that has fallen out is collected. The amount and texture of the hair are then analyzed.
If pathological hair loss is discovered, the causes should be examined more closely, as they can be very diverse. In addition to stress or medications, nutritional deficiencies or excesses, including possible vitamin D deficiency, can also cause hair loss.
Anyone who suspects a vitamin D deficiency can have their blood values tested. A defect should be remedied as quickly as possible as it can have far-reaching consequences. Based on the blood values, sensible daily doses can be determined. The German Society for Nutrition recommends 800 IU of vitamin D per day. If blood values are too low, the doctor will prescribe significantly higher amounts. Both a deficiency and an overdose can have negative consequences for the body.
Hair loss: what causes low vitamin D levels?
Vitamin D is the only vitamin that the body can produce itself. But for this it needs enough sunshine per day. In order to cover your daily vitamin D requirements, you need to spend time outdoors, as the Robert Koch Institute (RKI) emphasizes. In order to produce enough vitamin D, the body needs UV-B radiation in a specific wavelength – namely between 290 and 315 nanometers. This radiation intensity is seasonal below the 35th parallel. In Germany, according to the Swiss Federal Office of Public Health, people with light skin sometimes have to spend up to 2.5 hours a day outdoors in winter in order to synthesize enough vitamin D. People with darker skin can hardly or not at all achieve the required values in this country in winter. Therefore, according to the RKI, low vitamin D levels in the blood can occur, especially in the dark season.
