Lower level of vitamin D3 is associated with susceptibility to acute lower respiratory tract infection (ALRTI) and severity: a hospital based study in Chinese infants

Background: Acute lower respiratory tract infection (ALRTI) has been attributed to a major cause of global child mortality. Micronutrient deficiencies have been associated with susceptibility to ALRTI. Vitamin D is an immunomodulatory molecule and its deficiency is more prevalent in ALRTI children. The present hospital based investigation aimed to decipher association of vitamin D with ALRTI in Chinese infants. Methods: Total of 110 infants, diagnosed with ALRTI and their mother enrolled in the present study. Matched healthy infants belonging to similar areas were included as healthy controls. Plasma levels of 25-OH vitamin D in all cases, their mothers and controls were quantified by enzyme linked immunosorbent assay (ELISA). Results: Plasma levels of 25-OH vitamin D was significantly lower in ALRTI cases than healthy controls (P<0.0001). Furthermore, infants with Pneumonia displayed reduce levels of vitamin D-3 with reference to healthy controls and no statistical significant difference was noticed between Pneumonic infants and subjects with Bronchiolitis. A positive correlation was detected in plasma levels 25OH vitamin D in ALRTI cases and their respective mothers (P<0.0001, r=0.57). Conclusion: Lowered plasma level of 25-OH Vitamin D is linked with susceptibility to ALRTI. Positive correlation of vitamin D3 in ALRTI cases and their mothers indicated supplementation of vitamin D to pregnant women may reduce the incidence of ALRTI in Chinese children.