Growth, thiamin status, erythrocyte fatty acid composition, and visual acuity in fullterm infants fed breastmilk, formula, or evaporated milk

The effects of feeding breastmilk (BM), commercial formulas (F), or evaporated milk formula (EM) on growth, thiamin status, erythrocyte phosphatidylethanolamine (PE) fatty acid composition and visual acuity in 100 healthy full term infants were determined. Growth, thiamin status, and erythrocyte PE fatty acid composition was determined at birth, 3, and 6 months of age. Thiamin status was assessed by determining the erythrocyte transketolase activity (TKA) and the fatty acid composition of milk and blood was determined by gas-liquid-chromatography. Preferential looking acuity was assessed at 3 and 6 months of age using the acuity card procedure. -- There were no significant differences in weight, length, or head circumference between any feeding groups. However, daily weight gain between three and six months was significantly lower for the BM group (weight gain: ﻌ ± SD, BM 15.5 ± 4.0 g, F= 20.4 ± 5.8 g, EM = 20.2 ± 6.8 g, p < 0.05). As well, breastfed infants had slightly lower head circumference growth velocity between three and six months of age. -- There were no differences in the thiamin pyrophosphate effect between groups, however, BM infants had significantly lower transketolase activity than the F group which correlated with energy but not thiamin intake. -- The breastmilk obtained from mothers in the study contained on average (% total fatty acids by weight), 12.1 % linoleic acid (18:2(n-6)), 2.1% linolenic (18:3(n-3)), and 0.2% docosahexaenoic acid (22:6(n-3)). Infants in the F group consumed either Similac or Enfalac. Similac contained 30.5% 18:2(n-6), and 4.9% 18:3(n-3). Enfalac contained 17.1% 18:2(n-6) and 1.8% 18:3(n-3). EM contained (% total fatty acids) 2.1% 18:2(n-6), and 0.8% 18:3(n-3). Only breastmilk contained 22:6(n-3). -- In the circulation, F fed and EM fed infants had lower arachidonic acid (20:4(n-6)) at 3 months (p < 0.05) than BM fed infants (ﻌ ± SD, 20.3±2.8, BM, 18.3 ± 2.7, F, 18.7 ± 2.7, EM, % total fatty acids) but not at 6 months, and EM fed infants had lower adrenic acid (22:4(n-6)) at both 3 and 6 months. 22:6(n-3) was the highest in the BM group at both 3 (6.0 ± 1.7,BM, 3.1 ± 0.8, F, 4.1 ±0.9, EM, % total fatty acids) and 6 months of age (5.3 ± 1.6, BM, 2.9 ± 0.8, F, and 4.2 ± 1.3, EM, % total fatty acids) followed by EM then F. Visual acuity was higher in the BM group than EM (3.86 ± 0.29 cycles/degree vs 3.29 ± 0.41, 3 mos, 9.03 ± 0.29 vs 7.54 ± 0.25,6 mos, p < 0.05) with intermediate values in the F group (NS compared to EM and BM). Differences seen in visual acuity may be due to the low 18:3(n-3) in EM of 0.3 % of energy and are not reflective of 22:6(n-3) in circulation. -- From the results of the present study it appears that EM formulas may not meet the essential fatty acid requirements for optimal visual acuity, however, it may be adequate for thiamin and optimum growth. The differences seen in the BM group in growth and TKA can be related to lower energy intakes and do not indicate any deficiencies

Vitamin D deficiency and whole-body and femur bone mass relative to weight in healthy newborns

BACKGROUND: Vitamin D is required for normal bone growth and mineralization. We sought to determine whether vitamin D deficiency at birth is associated with bone mineral content (BMC) of Canadian infants. METHODS: We measured plasma 25-hydroxyvitamin D [25(OH)D] as an indicator of vitamin D status in 50 healthy mothers and their newborn term infants. In the infants, anthropometry and lumbar, femur and whole-body BMC were measured within 15 days of delivery. Mothers completed a 24-hour recall and 3-day food and supplement record. We categorized the vitamin D status of mothers and infants as deficient or adequate and then compared infant bone mass in these groups using nonpaired t tests. Maternal and infant variables known to be related to bone mass were tested for their relation to BMC using backward stepwise regression analysis. RESULTS: Twenty-three (46%) of the mothers and 18 (36%) of the infants had a plasma 25(OH)D concentration consistent with deficiency. Infants who were vitamin D deficient were larger at birth and follow-up. Absolute lumbar spine, femur and whole-body BMC were not different between infants with adequate vitamin D and those who were deficient, despite larger body size in the latter group. In the regression analysis, higher whole-body BMC was associated with greater gestational age and weight at birth as well as higher infant plasma 25(OH)D. CONCLUSION: A high rate of vitamin D deficiency was observed among women and their newborn infants. Among infants, vitamin D deficiency was associated with greater weight and length but lower bone mass relative to body weight. Whether a return to normal vitamin D status, achieved through supplements or fortified infant formula, can reset the trajectory for acquisition of BMC requires investigation