Nutritional supplements taken to prevent hair loss may actually destabilize hair follicles, with experts warning that excess intake can be more dangerous than deficiency.
The number of patients seeking medical treatment for hair loss reached 237,617 in 2024, up 13.9% from 208,601 in 2015, according to the National Health Insurance Service on Monday. Total medical expenses for hair loss patients during the same period surged 84.6%, from approximately 24.7 billion won to 45.6 billion won.
These figures cover only pathological hair loss conditions eligible for insurance coverage, such as alopecia areata and seborrheic dermatitis. The medical community estimates that the actual hair loss population is far larger when including age-related and hereditary hair loss as well as non-covered treatments.
Losing 50 to 70 strands a day is considered normal, but losing more than 100 strands while shampooing should raise suspicion of pathological hair loss.
Vitamin A is a representative ingredient at risk of overconsumption. The Ministry of Health and Welfare sets the daily upper intake limit of vitamin A for adults at 3,000㎍ RE. Taking multivitamins, eye health products, and skin supplements simultaneously can result in overlapping vitamin A content, pushing total intake close to this ceiling.
The American Academy of Dermatology explains that excessively high vitamin A levels in the body can trigger telogen effluvium, a condition in which hair falls out prematurely without completing its growth phase. Particular caution is needed for those taking high-dose retinol supplements long-term or using isotretinoin, a high-strength acne medication.
Conversely, extreme low-calorie diets also cause hair loss. The main component of hair is keratin protein. Under severe protein deficiency, the body first reduces energy supply to organs not directly essential for survival, such as hair follicles.
Dermatologists point out that maintaining a diet of less than 1,000 kcal and 30 grams of protein per day for two to three months or longer can trigger nutritional deficiency hair loss. Excessive intermittent fasting and replacing meals solely with salads represent typical risk patterns of extreme low-protein dieting.
Excessive consumption of raw egg whites is another easily overlooked risk factor. The avidin protein contained in egg whites interferes with the intestinal absorption of biotin, which is involved in keratin synthesis.
According to the U.S. National Institutes of Health (NIH), prolonged consumption of large amounts of raw egg whites increases the risk of biotin deficiency, which is recognized as one of the causes of hair loss. Avidin is denatured when heated above 70 to 85℃, so thoroughly cooked eggs pose no problem.
