The idea that iron deficiency is a common cause of hair loss is less popular with United States based dermatologists. Chronic iron deficiency also leads to symptoms of anemia, spoon shaped nails, depression and general lethargy. Much dietary iron is supplied from red meat, chicken, and fish so vegetarians are most at risk of having a diet deficient in iron. Vitamin C deficiency can lead to an iron deficiency. Other individuals who may be at risk of iron deficiency include those who are heavy consumers of caffeine rich tea, coffee, and other drinks.
Caffeine reduces the net availability of iron supplied from food.
Alcohol abuse also reduces the availability of iron in the body. Note that iron excess can also cause a toxic telogen effluvium. See hemochromatosis for details. Zinc deficiency Extreme zinc deficiency is associated with multiple symptoms including diarrhea and eczema-like skin problems. Zinc is important in hair fiber production and a deficiency of the metal results in diffuse telogen effluvium of the scalp and body hair.