Sociodemographic and perinatal factors associated with vitamin D deficiency in exclusively breastfeeding infants in North Central Nigeria

Abstract

Background Exclusive breastfeeding is highly recommended in early infancy; however, there are concerns about breast milk meeting the vitamin D requirements of infants during this period. Objective This study aimed to determine the serum 25-hydroxyvitamin D (25-OHD) level of lactating mothers and their healthy exclusively breastfeeding young infants, and to ascertain the predictors of deficient 25-OHD (<20 ng/ml) in these infants in a tropical setting. Participants and methods Mother–infant pairs at the Federal Medical Centre, Keffi North Central Nigeria, were consecutively recruited over a 7-month period. The study participants were characterized and their serum 25-OHD was assayed using the chromatography method. Results A total of 111 mother–infant pairs were recruited. The mean (SD) infant age was 3.0 (1.4) months, while the mean (SD) maternal age was 27.5 (5.1) years, with 3.6% being teenagers. The mean (SD) 25-OHD of infants and mothers were 39.7 (25.7) and 33.9 (20.4) ng/ml, respectively. Twenty-six (23.4%) infants and 33 (30.6%) mothers had deficient 25-OHD. Low birth weight and underweight infants, as well as inadequate maternal diet and maternal 25-OHD deficiency were associated with deficient 25-OHD status in infants. Only inadequate maternal diet (odd ratio=3.529; 95% confidence interval=1.100–11.168; P=0.033) and maternal vitamin D deficiency (odd ratio=10.168; 95% confidence interval=3.455–29.920; P=0.001) independently predicted deficient 25-OHD levels in the infants. Conclusion About one of every five exclusively breastfeeding recruited infants had deficient 25-OHD levels and this is associated with modifiable factors. Maternal intake of vitamin D-rich food and vitamin D supplementation may be necessary to meet the vitamin D requirements of these mother–infant pairs.