Optimal vitamin A and suboptimal vitamin D status are common in Iranian infants

Aim: Investigation of serum concentrations of vitamins A and D in Iranian infants.

Methods: A descriptive cross-sectional study, investigating 7112 infants (15-23 months of age) from all regions of Iran, who attended health care centres from May 25 to June 2, 2001. Unequal clusters with unequal household sizes were sampled. Vitamin A and D levels were analysed with high-performance liquid chromatography.

Results: The mean (SD) concentration of vitamin A was 2.09 (0.83) μmol/L. At a national level, 0.7% of the infants had a level indicating deficiency, and 0.5% of the infants had insufficient concentrations of vitamin A, defined as serum concentrations <0.35 and <0.7 μmol/L retinol, respectively. A total of 88% of infants had optimal concentrations (>1.4 μmol/L). The mean (SD) concentration of vitamin D was 61.3 (31.4) nmol/L. Deficiency was found in 2.8% of infants (<25 nmol/L), and insufficiency in 32.9% (<50 nmol/L). Suboptimal and optimal concentrations were found in 44% and 20%, representing 50-75 and >75 nmol/L, respectively. Girls had lower vitamin D concentrations than boys (p = 0.006).

Conclusion: As in developed countries, vitamin A deficiency was rare in Iranian infants. Vitamin D deficiency was also rare, but 33% of infants had insufficient levels; this was more common in girls than boys.