4 Uncontrolled studies have suggested that injecting either the infant or the nursing mother with biotin may be an effective treatment for cradle cap. Older uncontrolled studies and case reports suggest that 4 mg per day of oral biotin might be sufficient for mild cases of cradle cap, but 10 mg per day was required for more severe cases. 7 Two more recent, controlled trials found oral biotin amounts of 4 or 5 mg per day to have no benefit. The support for using oral biotin to treat cradle cap must be considered weak at best. The role of biotin in adult seborrheic dermatitis has not been studied.
Some physicians claim that B-complex vitamins are useful in the treatment of seborrheic dermatitis.
An uncontrolled trial found that 10 mg per day of folic acid was helpful in 17 of 20 cases of adult seborrheic dermatitis. However, this study also found that oral folic acid did not benefit infants with cradle cap. 12 Injection of vitamin B12 was reported to improve lesions in 32 of 37 adult patients in an uncontrolled trial. 13 Oral administration of B12 has not been studied. Refer to the individual supplement for information about any side effects or interactions.