Lack of vitamin D and hair loss: what to know

Hair growth responds to nutrition, hormones, illness, medicines, genetics and physical stress. Low vitamin D can be considered during an assessment, yet it does not explain every type of hair loss. Diffuse shedding after an illness or major stress may fit telogen effluvium, while smooth patches can occur with alopecia areata. Gradual thinning at the hairline, part or crown may fit pattern hair loss. Scalp scale, broken hairs or tenderness call for a scalp examination because infection or inflammation may be involved.

Arrange a clinical review if shedding continues, the part is widening, or you see patches. A clinician may examine the scalp and ask about diet, recent illness, menstrual or hormonal changes, family history, styling tension and medicines. Vitamin D testing may be appropriate when your history or examination suggests a deficiency; avoid high-dose supplements without advice, because more is not automatically better. Use gentle washing, limit tight hairstyles and avoid pulling hairs while the cause is being clarified.

Seek prompt medical advice for rapidly enlarging bald patches, scalp pain, pus, marked redness, heavy scaling, broken hairs, or loss of eyebrows or eyelashes. A sudden change with fatigue, weight change or other new symptoms also deserves assessment. Earlier review can help distinguish shedding from inflammation, infection or a condition that needs targeted treatment.

Could my pattern of shedding fit telogen effluvium, pattern hair loss or another condition? Do I need vitamin D or other blood tests? Which supplements are suitable for me? Could a medicine, hairstyle or scalp problem be contributing?