Effects of Vitamin D Supplementation on Immune Function in Infants

Overview

Current study shows that vitamin D deficiency might affect human's immune function. Although breast milk is the best food of infants, however the vitamin D content in breast milk is low. Thus, breastfeeding infants are at high risk of vitamin D deficiency.Children's development and health are always the most important issues for parents. However, high prevalence of allergy in infants in Taiwan were not only with environmental factor which may also relate to their nutritional status. The aim of this study was to enroll breastfeeding infant at age of 4 month, and provide vitamin D supplement 10 μg daily until 6 month, to discuss the effects of vitamin D supplementation on immune function in infants.

Study plan to enroll breastfeeding infant at age of 4 month, and provide vitamin D (vitD) supplement 10 μg daily until 6 month. we also enroll 6 month-old infant as control group. All infants collected 5 ml artery blood and measured vitD nutritional status and immune function. Blood analysis contain complete blood count (CBC), differential count (DC), serum calcium, serum Parathyroid hormone (PTH), serum 25(OH)D3, serum total immunoglobulinE (IgE) and cell phagocytosis. Peripheral blood mononuclear cell (PBMC) in blood was separated and cultured with complete medium contain 10% fetal bovine serum (CM10), or with different mitogens, include lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate and ionomycin (PI) and house dust mite extract (HDM). PBMC are incubated at 37 ℃, 5% CO2 for 48 hours, and determined the expression of B cell with IgE receptor CD21 and CD23 and T regulatory cell with transcription factor Foxp3 by flow cytometry. All data were analyzed with SPSS 20.0. Infant sex and feeding type were analyzed by chi-square analysis. Difference between vitD supplement group and control group were analyzed by student's t test. Relationship between 25(OH)D3 and Calcium or PTH were analyzed by pearson correlation analysis. There was a significant difference when p-value was less than 0.05.