Otherwise healthy children have low levels of vitamin D and many have reduced bone mineral content, a new study says.
The study found that, of the almost 400 children studied, more than 12 per cent had vitamin D deficiency, which was defined as 20 nanograms per mL of blood or less. Forty per cent of the children had vitamin D levels below the recommended level of 30 nanograms per mL.
Of the children who were found to be vitamin D deficient, 32 per cent were found to have lower bone mineral levels after having wrist and knee X-rays. Three of the children showed signs of rickets, the bone-weakening disease that vitamin D deficiency can lead to.
The study also found that babies who were breastfed who did not receive vitamin D supplements and toddlers who drank a minimal amount of milk had a higher risk of vitamin D deficiency.
"Given the potential benefits of vitamin D on bone and other tissues and growing data supporting its immunomodulatory effects, the current findings support recommendations advocating for vitamin D supplementation for all young children," the authors concluded.
The authors also said that health problems in children related to a vitamin D deficiency could be going unnoticed, as kids are not routinely tested for vitamin D levels.
However, in an editorial that accompanied the study, Dr. James A. Taylor of the University of Washington in Seattle said that more study needs to be done on the potential short- and long-term benefits of vitamin D supplementation in children.
"Pending this research, the recommendations by Gordon et al that all young children should receive vitamin D supplementation and that children with risk factors should have periodic vitamin D levels obtained may be premature," Taylor wrote.
The authors point out that several U.S. states are reporting widespread vitamin D deficiency in children, as well as a resurgence of rickets.
This study was conducted by researchers from Children's Hospital in Boston, who analyzed data from almost 400 healthy children between the ages of eight and 24 months. The findings are published in the June issue of Archives of Pediatrics & Adolescent Medicine.
Abstract:
Prevalence of Vitamin D Deficiency Among Healthy Infants and Toddlers
Catherine M. Gordon, MD, MSc; Henry A. Feldman, PhD; Linda Sinclair, BA; Avery LeBoff Williams, BA; Paul K. Kleinman, MD; Jeannette Perez-Rossello, MD; Joanne E. Cox, MD
Objectives To determine the prevalence of vitamin D deficiency and to examine whether 25-hydroxyvitamin D (25OHD) concentration varies as a function of skin pigmentation, season, sun exposure, breastfeeding, and vitamin D supplementation.
Design Cross-sectional sample.
Setting Urban primary care clinic.
Participants Healthy infants and toddlers (N = 380) who were seen for a routine health visit.
Outcome Measures Primary outcomes were serum 25OHD and parathyroid hormone levels; secondary measures included data on sun exposure, nutrition, skin pigmentation, and parental health habits. Wrist and knee radiographs were obtained for vitamin D-deficient participants.
Results The prevalence of vitamin D deficiency ( 20 ng/mL) was 12.1% (44 of 365 participants), and 146 participants (40.0%) had levels below an accepted optimal threshold ( 30 ng/mL). The prevalence did not vary between infants and toddlers or by skin pigmentation. There was an inverse correlation between serum 25OHD and parathyroid hormone levels (infants: r = -0.27, P < .001; toddlers: r = -0.20, P = .02). In multivariable models, breastfeeding without supplementation among infants and lower milk intake among toddlers were significant predictors of vitamin D deficiency. In vitamin D-deficient participants, 3 participants (7.5%) exhibited rachitic changes on radiographs, whereas 13 (32.5%) had evidence of demineralization.
Conclusions Suboptimal vitamin D status is common among otherwise healthy young children. Predictors of vitamin D status vary in infants vs toddlers, information that is important to consider in the care of these young patients. One-third of vitamin D-deficient participants exhibited demineralization, highlighting the deleterious skeletal effects of this condition.
