Hypercarotenemia in children with Down's syndrome.

In previous reports, deficiencies in serum vitamin A were considered a frequent finding in persons with Down's syndrome. Based on this assumption, the regular determination of both serum carotene and vitamin A has been recommended for the preventive care of this population. In the author's preventive medicine clinic for children with Down's syndrome, we have checked these items routinely in 44 fasting patients (aged 14 months to 19 years). The author was surprised to find no patient with either a deficiency of carotene or vitamin A, but 14 patients had hypercarotenemia. Any known aetiology of this finding, such as excessive ingestion, diabetes mellitus or hypothyroidism, could not be verified. It has to be mentioned that the previous reports on serum carotene levels were based on determinations by conventional spectrophotometric methods (normal range: 50-670 micrograms/dl), whereas the author applied an improved method of high-performance liquid chromatography with a much lower normal range (50-750 micrograms/l). Further investigations are to be performed to verify these findings and to evaluate probable mechanisms of hypercarotenemia in persons with Down's syndrome.