From the Guidelines
Vitamin D plays a significant role in hair follicle health, and deficiency may contribute to hair loss, particularly in conditions like alopecia areata. The relationship between vitamin D and hair loss is complex, with vitamin D receptors found in hair follicles, suggesting a role in hair cycling and growth 1. Studies have shown that lower serum vitamin D levels are associated with alopecia areata, and vitamin D deficiency is common in patients with this condition 1. For example, a case-control study found that 91% of patients with alopecia areata had vitamin D deficiency, compared to 33% of healthy controls 1. Another study found an inverse association between serum vitamin D levels and disease severity in alopecia areata patients 1. However, a prospective cohort study found no significant difference in the risk of developing alopecia areata between individuals with high and low vitamin D levels 1. Despite this, maintaining adequate vitamin D levels is essential for overall hair health, and supplementation may be beneficial for individuals with deficiency. The recommended daily intake of vitamin D varies, but typical supplementation ranges from 1,000-4,000 IU daily, depending on individual levels and needs 1. In addition to supplements, vitamin D can be obtained through sunlight exposure, fatty fish, fortified dairy products, and egg yolks. Other essential nutrients for hair health include iron, zinc, biotin, and protein. It is crucial to address vitamin D deficiency as part of a comprehensive approach to treating hair loss, rather than relying solely on supplementation. Therefore, individuals experiencing hair loss should have their vitamin D levels checked and consider supplementation if deficient, under the guidance of a healthcare provider. Key points to consider:
- Vitamin D receptors are present in hair follicles, indicating a role in hair growth and cycling
- Lower serum vitamin D levels are associated with alopecia areata
- Vitamin D deficiency is common in patients with alopecia areata
- Maintaining adequate vitamin D levels is essential for overall hair health
- Supplementation may be beneficial for individuals with vitamin D deficiency
- A comprehensive approach to treating hair loss should include addressing vitamin D deficiency, along with other essential nutrients and treatments.
From the Research
Vitamin D and Hair Loss
- Vitamin D plays a role in cell differentiation, proliferation, and apoptosis, and its deficiency has been associated with various forms of nonscarring hair loss 2.
- Research suggests that vitamin D is intricately involved in various signaling pathways of growth and differentiation of hair follicles, and most studies show an inverse relationship between serum vitamin D levels and non-scarring alopecias such as telogen effluvium, androgenetic alopecia, alopecia areata, and trichotillomania 3.
Role of Vitamin D in Different Types of Hair Loss
- Vitamin D deficiency has been associated with alopecia areata, and decreased vitamin D levels were observed in patients with alopecia areata, with a significant inverse correlation between vitamin D levels and duration/severity of the disease 4.
- A study found a significant correlation between vitamin D deficiency and the severity of androgenetic alopecia, suggesting that vitamin D may play a role in the premature onset of androgenetic alopecia 5.
- Vitamin D deficiency is also associated with scarring alopecia, although conclusive studies to demonstrate the benefit of vitamin D administration in correcting hair loss and managing these conditions are lacking 3.
Mechanism of Vitamin D in Hair Growth
- Vitamin D affects the hair cycle and plays an important role in immune regulation, cell growth, differentiation, and maintenance of hair cycle 4.
- Micronutrients such as vitamins and minerals, including vitamin D, play an important role in normal hair follicle development and immune cell function, and deficiency of such micronutrients may represent a modifiable risk factor associated with the development, prevention, and treatment of alopecia 6.
Future Research Directions
- Further studies are needed to determine the effect of specific micronutrient supplementation on hair growth in those with both micronutrient deficiency and non-scarring alopecia 6.
- Large double-blind placebo-controlled trials are required to establish any association between hair loss and vitamin D deficiency, and to validate the findings of existing studies 3, 5.