Prevalence of vitamin D deficiency among healthy infants and toddlers.
OBJECTIVE
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.


METHODS
Cross-sectional sample.


METHODS
Urban primary care clinic.


METHODS
Healthy infants and toddlers (N = 380) who were seen for a routine health visit.


METHODS
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 (< or =20 ng/mL) was 12.1% (44 of 365 participants), and 146 participants (40.0%) had levels below an accepted optimal threshold (< or =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.
Divisions of Adolescent Medicine and Endocrinology, Children's Hospital Boston, 300 Longwood Ave, Boston, MA 02115, USA. catherine.gordon@childrens.harvard.edu
Catherine M
CM
Gordon
Henry A
HA
Feldman
Linda
L
Sinclair
Avery LeBoff
AL
Williams
Paul K
PK
Kleinman
Jeannette
J
Perez-Rossello
Joanne E
JE
Cox
D002669:Child Welfare / Q000706:statistics & numerical data*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007229:Infant Welfare / Q000706:statistics & numerical data*; D007231:Infant, Newborn; D007717:Knee / Q000000981:diagnostic imaging; D008019:Life Style; D008297:Male; D009752:Nutritional Status; D015995:Prevalence; D011320:Primary Health Care; D011859:Radiography; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014505:Urban Population / Q000706:statistics & numerical data*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D014953:Wrist / Q000000981:diagnostic imaging
D014807:Vitamin D; C104450:25-hydroxyvitamin D