Hair loss is a symptom of some diseases that are caused by vitamin deficiency, such as scurvy. Adding certain foods and vitamins to the diet may help slow or stop abnormal hair loss; however, you should consult with a medical professional before taking supplements or making significant changes to your diet.

Protein

A protein deficiency may cause hair loss, according to Harvard University Health Services, because hair is made of protein. To prevent hair loss, you need 0.36 g per pound of body weight per day; for example, if you weigh 150 pounds, you require about 54 g protein per day. Vegetarians may need to take in more because the body does not absorb plant proteins as well as it does animal proteins. Pregnant women and those who are weight lifting to build muscle require more protein than others.

ZInc

A zinc deficiency may cause hair to fall out, reports Huntington College of Health Sciences. The recommended dose is 15 mg per day. The College states that many Americans are low in this mineral, which facilitates cell division in the hair follicle. The hair follicle is where hair begins its growth cycle.

Folic Acid

Folic acid also promotes cell division. A deficiency of folic acid can lead to hair loss and graying, as well as to anemia and fatigue, according to Huntington College of Health Sciences. The College recommends between 400 and 800 mcg a day.

Calcium

A calcium deficiency may cause hair loss, reports Huntington College of Health Sciences. It suggests that many Americans are deficient in calcium even though it is readily available in dairy products or inexpensive vitamin supplements. The suggested daily level is 100 to 200 mg a day, but taking high doses of calcium without magnesium can be harmful.

Iodine

Iodine deficiency can lead to hair loss, because iodine is necessary for proper thyroid function, states Huntington College of Health Sciences. When the thyroid is underactive, hair loss can occur. The College suggests 112 to 225 mcg of iodine per day.