What vitamin makes your hair thin? Vitamin D: When vitamin D is low, the hair may thin or stop growing. Zinc: Zinc deficiency can cause similar hair loss to iron and may also damage any remaining hair, causing it to break.
How much biotin should I take if my hair is thinning? 2-5 milligrams
What are the side effects of biotin hair growth? No side effects have been reported for biotin in amounts up to 10 milligrams a day. However, check with your health care professional if you notice any unusual effects while you are taking it.