Purpose: A randomized, controlled clinical trial was conducted in Indonesia to study the response of Bitot's spots to a 100,000-IU dose of vitamin A, which is known to be associated with fewer acute side effects than the currently recommended 200,000-IU dose.
Methods: A total of 114 children (ages 13 to 59 months) with Bitot's spots were given an ocular examination; serum retinol concentration was measured, and the relative dose response test carried out. After administering one 100,000- or 200,000-IU oral dose of vitamin A, ocular examinations were repeated weekly for seven weeks and then biweekly for 20 more weeks, or until lesions were healed on two consecutive examinations.
Results: Either dose of vitamin A was similarly effective in healing Bitot's spots. The most important factor in predicting responsiveness to treatment was baseline serum retinol concentration: children with lower pretreatment concentrations were more likely to have responsive lesions. No child had a relapse within the first three months after treatment. However, by six months, children who had received the higher dose were 82% less likely to have a relapse compared with children who had received the lower dose.
Conclusions: Although either a 100,000- or 200,000-IU dose of vitamin A is similarly effective in healing Bitot's spots, a 200,000-IU dose provides longer protection. This benefit justifies the higher rates of transient mild side effects associated with the 200,000-IU dose. The current 200,000-IU dose of vitamin A recommended by the World Health Organization for prophylactic dosing should not be reduced.