Vitamin D Intake and Meeting Recommendations Among Infants Participating in WIC Nationally

Abstract

Objective: To report and examine associations with infant vitamin D intake and meeting recommendations among a national sample participating in Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).

Design: Secondary analysis from the 2013-2015 WIC Infant Toddler Feeding Practices Study-2.

Participants: US Infants.

Variables measured: Total reported vitamin D intake from diet and supplementation at the time of data collection.

Analysis: Descriptive statistics and generalized estimating equations.

Results: The median total vitamin D intake ranged from 5.43 (95% confidence interval, 5.40-5.46) mcg/d at month 1 to 8.18 (95% confidence interval, 8.11-8.20) mcg/d at month 13, with 16% to 36% of infants meeting the infant vitamin D recommendation over that time. Overall, 6% to 12% of all participants reported supplementation across all time points. Although most (between 78% to 98%) of supplemented breastfed infants met the recommendation, very few were supplemented as a group. Hence, breastfed infants were less likely to meet the recommendation than those who were formula fed across at time points except month 1 (P < 0.001 for all). Whereas infant age, feeding type, and/or their interaction were significant predictors of both receiving supplementation and meeting the recommendation, mother/caregiver nativity (P = 0.006) and parity (P = 0.01 and P < 0.001) predicted receiving supplementation, and child sex (P < 0.001) and mother/caregiver race/ethnicity (P < 0.001) predicted meeting the recommendation.

Conclusions and implications: Among a national sample of infants participating in WIC between 2013-2015, a high proportion were not meeting the current vitamin D recommendation. The WIC program is 1 resource for promoting strategies for increasing the number of American infants meeting D recommendations, but a coordinated approach involving other health care providers is likely needed. Future research exploring the reason for lack of supplementation, from both the perspective of parents and providers and the clinical impact of low vitamin D intake, is warranted.

Keywords: WIC; infants; public health guidelines; vitamin D; vulnerable populations.