Neonatal Intensive Care Unit, University Hospital of Ioannina, Ioannina, Greece.
Eur J Clin Nutr. 2012 Feb;66(2):224-30. doi: 10.1038/ejcn.2011.158. Epub 2011 Sep 7.
BACKGROUND/OBJECTIVES: Preterm infants are at risk for low vitamin D but documentation on late-preterm infants is sparse. This prospective study monitored longitudinally vitamin D and parathormone (PTH) levels in late-preterm formula fed infants during the first year of life, taking into consideration in utero and postnatal growth, and season and diet.
SUBJECTS/METHODS: The study population comprised 128 infants of gestational age (GA) 32-36 weeks, of which 102 were appropriate (AGA) and the remaining 26 were small for GA (SGA). Serum levels of vitamin D (25(OH)D), PTH calcium, phosphate (P) and alkaline phosphate were estimated at 2 and 6 weeks, and at 3, 6, 9 and 12 months of age.
The 25(OH)D levels were relatively low at 2 and 6 weeks in both AGA and SGA infants (21±11, 20±7 ng/ml and 25±16, 23±8 ng/ml, respectively), but increased at 6 months (45±14, 47±10 ng/ml) and remained stable thereafter. SGA infants had lower 25(OH)D levels at 9 and 12 months (AGA 45±14, 47±18 ng/ml vs SGA 38±13, 37±13 ng/ml, P<0.05). Deficiency of 25(OH)D (<20 ng/ml) was found in 18.5% of measurements in 92 (72%) infants, and its insufficiency (20-32 ng/ml) was found in 29.2% of measurements in 99 (77.3%) infants. Most measurements with vitamin D <32 ng/ml were observed at the first three study points, where PTH showed an inverse association with 25(OH)D, reaching a plateau thereafter.
Late-preterm, formula fed infants may have suboptimal vitamin D levels and elevated PTH, especially, during the first 3 months. Those born SGA may have lower vitamin D levels up to the end of the first year of life.
背景/目的：早产儿存在维生素 D 水平低的风险，但关于晚期早产儿的相关数据较为缺乏。本前瞻性研究监测了 128 例胎龄为 32-36 周的晚期早产儿配方奶喂养婴儿在出生后第一年的维生素 D 和甲状旁腺激素 (PTH) 水平，同时考虑了宫内和产后生长情况、季节和饮食。
受试者/方法：研究人群包括 128 名胎龄（GA）为 32-36 周的婴儿，其中 102 名婴儿为适于胎龄儿（AGA），其余 26 名婴儿为小于胎龄儿（SGA）。在 2 周和 6 周时，以及 3、6、9 和 12 个月时，测定血清维生素 D（25(OH)D）、PTH、钙、磷（P）和碱性磷酸酶的水平。
AGA 和 SGA 婴儿在 2 周和 6 周时的 25(OH)D 水平均相对较低（分别为 21±11、20±7ng/ml 和 25±16、23±8ng/ml），但在 6 个月时增加（45±14、47±10ng/ml），此后保持稳定。9 个月和 12 个月时，SGA 婴儿的 25(OH)D 水平较低（AGA 为 45±14、47±18ng/ml，SGA 为 38±13、37±13ng/ml，P<0.05）。92 名（72%）婴儿中有 18.5%的测量值存在 25(OH)D 缺乏（<20ng/ml），99 名（77.3%）婴儿中有 29.2%的测量值存在 25(OH)D 不足（20-32ng/ml）。大多数 25(OH)D<32ng/ml 的测量值出现在前 3 个研究点，此时 PTH 与 25(OH)D 呈负相关，此后达到平台期。
晚期早产儿配方奶喂养婴儿可能存在维生素 D 水平不足和甲状旁腺激素升高的情况，尤其是在前 3 个月。出生时为 SGA 的婴儿可能会出现维生素 D 水平较低的情况，直到 1 岁。
