Table 2: Infant and maternal characteristics.

CharacteristicMean (± SD)

Gestational age, weeks39.3 ± 1.1
Weight-for-age percentile
(CDC 2000 growth charts)
52.1 ± 26.4
Feeding type, n (%)
 Formula18 (28.6)
 Breastfeed < 6 moψ31 (49.2)
 Breastfeed > 6 mo14 (22.2)
Season of birth, n (%)
 Summer/fall32 (50.8)
 Winter/spring31 (49.2)
Infant’s vitamin D status
 Deficient¹19 (30.2)
 Sufficient44 (69.8)
Mother’s age at birth, years27.7 ± 6.1
Mother’s race, n (%)
 White41 (65.1)
 First nations10 (15.9)
 Asian7 (11.1)
 Black2 (3.2)
 Other3 (4.8)
Mother’s vitamin D status
 Deficient²23 (36.5)
 Sufficient40 (63.5)

¹Infant: 25(OH)D 27.5 nmol/L, ²Mother: 25(OH)D 37.5 nmol/L—Institute of medicine dietary reference intakes [8, 9]. ψMay include exclusive breastfeeding and mixed feeding. Exclusive breastfeeding refers to an infant receiving only breast milk without additional liquid or solid food.