Hair & Nutrition

Various genetic or acquired malabsorption deficiencies or insufficient uptake of nutrients can influence hair growth. The diagnosis is established through a careful history and clinical examination. Typical clues are a diffusely positive pull test confirmed by a trichogram or digital phototrichogram, changes in hair diameter, structure and strength including broken or brittle hairs, and pigment changes seen in trichoscopy.
Laboratory blood tests confirm the specific deficiency. Relevant iron deficiency can be assumed at ferritin levels less than 40 mg/L. Specific treatment of the deficiency will lead to improved hair parameters within 3 to 6 months. Unspecific treatment of hair loss without confirmed deficiencies has only been effective in telogen effluvium with a supplement containing L-cysteine, but otherwise can not generally be recommended.
Hair follicle cells have a high turnover. Their active metabolism requires a good supply of nutrients and energy. 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. Combined deficiencies are not uncommon, especially in malnutrition.
In developed countries, hair growth disorders caused by nutritional deficiencies in healthy individuals are rare and tend to be overestimated by patients and physicians, especially concerning vitamins. National and International Institutions have established recommended daily allowances of manynutritional components. In the United States, the National Institutes of Health has published recommendations for the daily reference intake of micronutrients and macronutrients and the maximum daily intake that will likely not cause adverse effects.
Unspecifically, dietary supplements have been used traditionally to improve hair growing process, a few of them have been systematically studied in humans and animals.
The diagnosis is based on a careful history of nutritional habits including 3 to 4 months before the hair problem. Clinical signs include a diffusely positive pull test, hair diameter, color, and quality changes or fragility as well as skin and nail changes. The latter changes are easier to recognize by holding a contrasting white or black paper (hair card) behind the tips of the hairs and by using trichoscopy and videotrichoscopy. A trichogram or digital phototrichogram may reveal increased rates of telogen. Laboratory blood tests should be targeted based on the suspected deficiency.
Hair analysis is often presented as a mechanism to diagnose intoxications and deficiencies as the reasons behind structural hair changes and hair loss. However, the lack of laboratory standards, evident correlation between the established nutritional status and hair components, deteriorates the use of hair analysis in a hair clinic.
Polluted air and several external factors may influence the hair content, while changes in the hair growth rate due to alterations in the nutritional status may affect the concentrations as well.
The diagnosis is based on a careful history of nutritional habits including 3 to 4 months before the hair problem. Clinical signs include a diffusely positive pull test, hair diameter, color, and quality changes or fragility as well as skin and nail changes. The latter changes are easier to recognize by holding a contrasting white or black paper (hair card) behind the tips of the hairs and by using trichoscopy and videotrichoscopy. A trichogram or digital phototrichogram may reveal increased rates of telogen. Laboratory blood tests should be targeted based on the suspected deficiency.
Furthermore, hair analysis is often marketed as a tool to diagnose deficiencies and intoxications as causes of hair loss and structural hair changes. However, the use of hair analysis in a hair clinic is very limited, because there are no laboratory standards and no clear correlation between hair components and thenutritional status has been established. The hair content can be influenced by polluted air and other external factors. Concentrations can also be influenced by changes in hair growth speed because of variations in nutritional status.