Nutrition and hair: deficiencies and supplements.

Hair follicle cells have a high turnover. A caloric deprivation or deficiency of several components, such as proteins, minerals, essential fatty acids, and vitamins, caused by inborn errors or reduced uptake, can lead to structural abnormalities, pigmentation changes, or hair loss, although exact data are often lacking. The diagnosis is established through a careful history, clinical examination of hair loss activity, and hair quality and confirmed through targeted laboratory tests. Examples of genetic hair disorders caused by reduced nutritional components are zinc deficiency in acrodermatitis enteropathica and copper deficiency in Menkes kinky hair syndrome.