Vitamin Deficiency & Thinning Hair in Women

Thinning hair and hair loss can be an unpleasant, even traumatic, experience for women. A review published in 2009 in the "Cleveland Clinic Journal of Medicine" reports that losing 100 to 150 hairs per day is considered normal. If your hair is thinning, it might be due to a nutrient deficiency, although there are other possible causes.

Woman brushing her hair (Image: Emma Innocenti/iStock/Getty Images)

Vitamin Imbalances

A deficiency in biotin, one of the B vitamins, can cause thinning hair in women -- so can being deficient in vitamin D, according to a review paper published in the June 2009 issue of the "Cleveland Clinic Journal of Medicine." Recommended dietary allowances for biotin and vitamin D are 30 and 15 micrograms per day, respectively. Biotin is present in yeast, sardines, egg yolks, soybeans, legumes, whole grains, nuts and nut butters, while fish, eggs, milk, yogurt, vitamin D-fortified foods and sunlight provide vitamin D. Getting more than about 10,000 international units of vitamin A daily can also lead to hair loss.

Mineral Deficiencies

Deficiencies in certain minerals can also cause thinning hair and hair loss in women. The American College of Dermatology and the 2009 review in the "Cleveland Clinic Journal of Medicine" both report that iron or zinc deficiency can cause hair loss. Women aged 19 to 50 require 18 milligrams of iron daily, pregnant women need 27 milligrams and women over age 50 need 8 milligrams of iron per day. Zinc requirements for women are 8 milligrams daily, with 11 milligrams during pregnancy. Iron- and zinc-rich foods include meat, poultry, seafood, legumes and fortified breakfast cereals. Dairy foods are also rich in zinc. A 4-ounce portion of lean ground beef provides about 3 milligrams of iron and 6 milligrams of zinc.

Macronutrient Deficiencies

Eating too few calories and getting too little protein and dietary fat -- especially essential fatty acids, which are fats your body requires daily -- can cause thinning hair and hair loss in women, according to the 2009 review in the "Cleveland Clinic Journal of Medicine." The National Heart, Lung and Blood Institute recommends that moderately active women consume 1,800 to 2,200 calories daily. For a 2,000-calorie-per-day diet, 44 to 78 grams per day, or 20 to 35 percent, should come from healthy fats. Nuts have about 12 to 14 grams of healthy fats per ounce, and plant-based oils providing 14 grams per tablespoon.The RDA of protein for women is 46 grams. Cottage cheese provides about 14 grams per 1/2 cup and grilled chicken breast about 26 grams per 3-ounce serving.

Other Causes

Stress, rapid weight loss, certain medications, heredity, illnesses, cancer treatments, a hair-loss disorder called alopecia, anemia or thyroid disease can cause a woman's hair to become thinner. Hormonal changes in the body, which often occur after giving birth or during menopause, might be another cause, as might poor hair care. For example, using too much heat, dye, bleach or other chemicals; too much shampooing or brushing, or pulling your hair too tight can cause loss of hair. If you're taking care of your hair and leading a healthy lifestyle but still shedding more hair than usual, it may be time to see a doctor.