Vitamin D deficiency in breastfed infants in Iowa.
OBJECTIVE
The purpose of this work was to assess the vitamin D status of breastfed infants living in Iowa (latitude: 41 degrees N).


METHODS
Blood samples and dietary records from 84 breastfed infants participating in another study were used for a survey of vitamin D status at 280 days of age. The vitamin D status of those (35 infants) who did not receive preformed vitamin D at 280 days of age (unsupplemented infants) was assessed longitudinally between 112 days and 15 months of age. Plasma 25-hydroxyvitamin D and, in most cases, parathyroid hormone and alkaline phosphatase were determined.


RESULTS
At 280 days of age, 10% of breastfed infants were vitamin D deficient (25-hydroxyvitamin D < 11 ng/mL). Deficiency was significantly more prevalent among dark-skinned infants and during winter and occurred exclusively in unsupplemented infants. During winter, 78% of unsupplemented infants were vitamin D deficient. During summer, only 1 infant who had dark skin pigmentation was vitamin D deficient. Longitudinal assessment of unsupplemented infants similarly showed that the majority of breastfed infants were vitamin D deficient during winter. Severe deficiency (25-hydroxyvitamin D < 5 ng/mL) was common and was accompanied by elevation of parathyroid hormone and alkaline phosphatase. The prevalence of vitamin D deficiency decreased with age but was still 12% at 15 months of age if no preformed vitamin D was received.


CONCLUSIONS
Vitamin D deficiency, including severe deficiency, was common among breastfed infants in Iowa who did not receive preformed vitamin D. Deficiency occurred mostly during winter but was not completely absent during summer. It affected infants with light as well as dark skin pigmentation. Consumption of preformed vitamin D from vitamin supplements or formula is effective in preventing vitamin D deficiency. Vitamin D supplementation should be provided to all breastfed infants.
Ziegler
Ekhard E
EE
Department of Pediatrics, University of Iowa Hospitals and Clinics, 200 Hawkins Dr, Iowa City, Iowa 52242, USA. ekhard-ziegler@uiowa.edu
Hollis
Bruce W
BW
Nelson
Steven E
SE
Jeter
Janice M
JM
D000328:Adult; D000367:Age Factors; D000469:Alkaline Phosphatase / Q000097:blood; D001942:Breast Feeding / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007484:Iowa / Q000453:epidemiology; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D011446:Prospective Studies; D044469:Racial Groups; D016032:Randomized Controlled Trials as Topic; D012621:Seasons; D012880:Skin Pigmentation; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology* / Q000209:etiology
D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase