Hair loss is becoming a common problem affecting many people. Environment, nutrition, medical conditions, and genetics are all contributing factors. Vitamin D3 deficiency, which is common in every region of the world, is also a contributing factor and one of the leading causes of hair loss. 

What is Vitamin D3?

Vitamin D3 is a fat-soluble nutrient that is essential for optimum health. There are dietary sources and supplements of Vitamin D3 which must be taken for the body to maintain adequate levels. Although not in active form, it is also present in the skin and can be activated only by sun exposure. The inactivated 7-dehydrocholesterol present in the skin is converted to cholecalciferol by UVB rays. Cholecalciferol is converted into an active form,1,25 dihydroxycholecalciferol (Vitamin D3) in the liver and kidneys. Vitamin D3 deficiency and Hair LossSun exposure of approximately five to ten minutes on bare skin at least two to three times per week can produce a substantial amount of Vitamin D3. Although sun exposure is essential, it breaks down quickly and can’t be stored for a long time resulting in rapid depletion of the stores, especially during the winter.

Role of Vitamin D3 in Causing Hair Loss

Many studies have shown that Vitamin D3 deficiency causes hair loss. Various autoimmune diseases are also linked with lower serum Vitamin D3 levels. Substantial evidence shows the anti-inflammatory and immunoregulatory effects that Vitamin D3 can have on our bodies. 


Vitamin D3 plays a role in the development of new hair follicles and improves hair growth. A Japanese study done in 2012 revealed that Vitamin D3 revives the dormant hair follicles and also creates new follicles. An autoimmune type of hair loss known as Alopecia Areata is linked to Vitamin D3 deficiency. It has been proven by assessing the serum Vitamin D3 in affected individuals, which is deficient in comparison to unaffected individuals.

Role of Vitamin D3 is also evidenced by the fact that patients with Vitamin D dependant Rickets type II have overall sparse body hair, frequently having the total body and scalp alopecia. These patients have mutations in the Vitamin D receptor (VDR) gene, which is typically immunoreactive for Vitamin D and shows activity in the anagen phase of the hair growth cycle. The mutations result in resistance against Vitamin D

Research evidence

Many clinical studies prove that Vitamin D3 deficiency can be one of the main causative factors of hair loss. Few studies which show a strong correlation of Vitamin D3 deficiency and hair loss are:

  • A study conducted aimed to evaluate the status of Vitamin D in patients with two autoimmune disorders to know the relation of Vitamin D deficiency with alopecia. So, they took the patients of alopecia areata and vitiligo separately. There were 86 patients with alopecia areata, 44 with vitiligo, and 58 healthy controls. Vitamin D levels were determined, and there is more prevalence of deficiency in patients with alopecia areata (90.7%) compared to patients with vitiligo (70.5%) and healthy controls (32.8%).
  • It is found in a study performed in Turkey that approximately 91% of patients who were being treated for alopecia areata have low levels of Vitamin D.
  • Another study published in ‘Skin Physiology and Pharmacology’ determined the relationship between Vitamin D and serum ferritin with Telogen effluvium and female pattern hair loss. The study concluded with the strong association of low levels of Vitamin D and ferritin with both types of hair loss.

Recommended Dosage of Vitamin D

The recommended dosage of Vitamin D for adults is 600 to 800 IU/l (15-20 mcg). Serum levels below 30ng/ml show deficiency and anyone having levels below 30ng/ml will have symptoms of Vitamin D deficiency. For these individuals, the guidelines of the Endocrine Society recommends a daily intake of 1500-2000 IU of Vitamin D to restore optimum levels in the body.


Sources Of Vitamin D

One must take care to get the recommended dosage of Vitamin D daily; otherwise, they’ll get deficient. There are different forms which can be used for Vitamin D ingestion:

  1. Sun Exposure: Vitamin is naturally synthesized in the body utilizing sunlight. If you spare 10-15 minutes in sunlight, then your body makes enough Vitamin D and stores remain replenished. The first defense is sun exposure if you are at risk of developing Vitamin D deficiency or if your deficiency level is not severe.
  2. Foods: If you are not exposed to sunlight than including the Vitamin enriched foods is another way to restore the body’s Vitamin D levels. Fish (fatty fish, salmon, mackerel), eggs, mushrooms, cod liver oils, and animal fats are all excellent sources of Vitamin D. Fortified food products such as milk and cereals can also be used.
  3. Supplements: if you are at risk of developing Vitamin D or have developed deficiency than starting the supplements is the best choice. Most multivitamin supplements contain 400 IU units of Vitamin D., But the doctor must decide your daily intake according to the level of deficiency. The maximum recommended daily intake must be limited to 4000 IU, not more than that. If you are too deficient, then you must need a high dose supplement; therefore, it is better to consult a doctor before starting supplements. It is recommended to take supplements with meals to avoid any undesirable side effects.


Vitamin D is an essential nutrient for health. Its deficiency not only makes hair brittle and dry, causing hair loss but also affects bones, teeth, muscles, heart, and mood. Vitamin D deficiency is not an incurable or unpreventable deficiency. The only way to speedy cure is timely diagnosis of the condition. If you are undergoing hair loss treatment, then taking Vitamin D supplements can complement the treatment results.