Abstract
BACKGROUND/OBJECTIVES Vitamin D deficiency has been associated with impaired resistance to infection, which may be mediated by alterations in cytokine responses. We investigated the effect of vitamin D supplementation to infants on whole blood in-vitro cytokine production and on the inflammatory marker, plasma C-reactive protein (CRP). SUBJECTS/METHODS Blood samples were taken at 6 months of age from infants participating in the DIVIDS (Delhi Infant Vitamin D Supplementation) randomized controlled trial of weekly vitamin D supplements (1400 IU = recommended intake) from birth to 6 months with the aim of decreasing mortality and severe morbidity. We measured plasma CRP and whole blood in-vitro production of tumour necrosis factor-α (TNFα), interferon-γ (INFγ), interleukin (IL)-10 and IL-13 following no stimulation or stimulation with lipopolysaccharide or phytohemagglutinin. RESULTS Although the intervention improved vitamin D status in a severely deficient population, there were no differences between treatment groups in plasma CRP or in the production of any of the cytokines in either unstimulated or stimulated cultures. Recent illness had limited association with immunological markers. Plasma 25-hydroxyvitamin D levels were not associated with CRP or production of any cytokines. CONCLUSIONS Vitamin D supplementation did not affect plasma CRP or whole blood cytokine production of vitamin D-deficient low birth weight infants. This is consistent with the lack of effect of vitamin D on mortality and severe morbidity among infants in the DIVIDS trial.
