Normative Data for Bone Mass in Healthy Term Infants from Birth to 1 Year of Age

Table 2

Infant and maternal characteristics.

Characteristic	Mean (± SD)
Gestational age, weeks	39.3 ± 1.1
Weight-for-age percentile; (CDC 2000 growth charts)	52.1 ± 26.4
Feeding type, n (%)
Formula	18 (28.6)
Breastfeed < 6 mo^ψ	31 (49.2)
Breastfeed > 6 mo	14 (22.2)
Season of birth, n (%)
Summer/fall	32 (50.8)
Winter/spring	31 (49.2)
Infant’s vitamin D status
Deficient¹	19 (30.2)
Sufficient	44 (69.8)
Mother’s age at birth, years	27.7 ± 6.1
Mother’s race, n (%)
White	41 (65.1)
First nations	10 (15.9)
Asian	7 (11.1)
Black	2 (3.2)
Other	3 (4.8)
Mother’s vitamin D status
Deficient²	23 (36.5)
Sufficient	40 (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.