Serum vitamin D levels in lactating mothers and their exclusive breastfeeding infants with symptoms of rickets

Objective To evaluate the vitamin D status in postpartum women during lactation and their exclusively breastfed infants with symptoms of rickets at 4–6 weeks after birth. Factors associated with breastfed infant serum vitamin D status were also determined. Methods One hundred and two exclusively breastfeeding infants with symptoms of nutritional rickets and their mothers were recruited in this study. Sociodemographic and clinical data including blood samples were collected during their visit to the children healthcare counseling clinic. Lactating mothers and their nursing infants were classified into sufficient, insufficient, and deficient according to serum 25(OH)D levels. Multivariate logistical regression model was used to analyses the final adjusted odds ratio and 95% CI. Results The prevalence of vitamin D sufficiency in lactating mother and exclusively breastfed infants were 8.7% and 40.2%, respectively. Final multiple logistic regression showed that infant daily vitamin D intake and body weight were statistically significantly associated with vitamin D status. Infant who had a vitamin D intake of > 400 IU per day (adjusted OR, 3.47; 95%CI, 1.06–11.30) was more likely to be vitamin D sufficiency. Infant with a higher body weight was associated with vitamin D sufficient status (adjusted OR, 2.01; 95%CI, 1.11–3.66). Conclusions Our study shows a very low prevalence of 25(OH)D sufficiency in lactating mothers, and a moderate vitamin D sufficiency in the exclusive breastfeeding infants with symptoms of rickets. Infant daily vitamin D intake and body weight were related to their vitamin D status. Findings of this study indicate the importance of vitamin D supplementation to maintain sufficient 25(OH)D levels in infants.