No association between serum 25-Hydroxyvitamin D-3 level and performance on psychometric tests in NHANES III

Background: Animal studies and in vitro experiments indicate that vitamin D is involved in a diverse range of neurobiological functions. We had the opportunity to examine the relationship between serum 25-hydroxyvitamin D 3 [25( OH) D] levels and performance on various cognitive tasks, based on a large, representative community sample. Methods: Three age groups were available from the population-based NHANES III survey: adolescent group (n = 1,676, age range 12 - 17 years), adult group (n = 4,747, 20 - 60 years), elderly group (n = 4,809, 60 - 90 years). The associations between eight psychometric measures and serum 25(OH) D were assessed. Results: In the adolescent and adult groups, none of the psychometric measures were associated with 25(OH) D levels. In the elderly group there was a significant difference between 25(OH) D quintiles performance on a learning and memory task; however, those with the highest quintile of 25(OH) D were most impaired on the task, contrary to the hypotheses. Conclusion: Lower 25(OH) D levels were not associated with impaired performance on various psychometric measures. While it remains to be seen if chronic exposure to low 25( OH) D levels alters brain function in the long term, this cross-sectional study suggests that 25( OH) D levels do not influence neurocognitive performance. Copyright (c) 2007 S. Karger AG, Basel.