If your system doesn’t have enough vitamin D, new hair growth can be stunted. Vitamin D deficiency has been associated with alopecia, an autoimmune condition that causes bald patches on the scalp and other parts of the body. Vitamin D is generated by your body when it comes into direct contact with the sun’s rays. Fatty fish, cod liver oil, certain mushrooms, and fortified foods are all good sources of vitamin D.
Vitamin D assists in stimulating new and old hair follicles. A 2014 study published in Molecular Endocrinology found that hair regrew in mice two weeks after introducing vitamin D receptors in the VDR null rodents.