Adhikari K M, Somani B L, Kalra Suprita, Mathai S S, Arora M M
Senior Advisor (Paediatric) INHS Dhanvantari, Port Blair.
Scientist G & Professor, Department of Biochemistry, AFMC, Pune - 40.
Med J Armed Forces India. 2011 Apr;67(2):142-6. doi: 10.1016/S0377-1237(11)60013-0. Epub 2011 Jul 21.
Role of vitamin A in reducing the mortality in infants more than six months of age is well known. Supplementing newborn infants with vitamin A within 48 hours of birth reduces infant mortality by almost a quarter, with the greatest benefit to those of low birth weight (LBW). Studies that could highlight deficiency states in neonates, particularly LBW babies by objective measurement of vitamin A levels would help in formulating the recommendations to supplement these babies with vitamin A.
Cord blood plasma vitamin A levels of 154 LBW babies with birth weight in the range of 1505-2455 were analysed for plasma vitamin A (retinol) levels by HPLC method. Samples of 55 babies with normal birth weight were also analysed. LBW babies were divided into two subgroups of preterm LBW and LBW-term small for gestational age (SGA).
Of the 154 babies with LBW, 92 were preterm LBW and 52 were LBW-term SGA. Mean cord blood plasma vitamin A levels were significantly lower in the preterm LBW group (n = 92) compared to levels observed in babies with normal birth weight (n = 55) and LBW-term SGA subgroups (n = 62). There was no significant difference in the mean vitamin A values between the normal birth weight babies and LBW-term SGA group. There was significant positive correlation of cord blood vitamin A levels with birth weight in the entire set of (n = 154) LBW babies (r=0.37, P < 0.0001).
This study revealed significantly lower cord blood vitamin A levels in the preterm LBW babies. The level of vitamin A in LBW babies also correlated with their birth weight. There are enough evidence to support causative association between vitamin A deficiency state and neonatal morbidity. Simple interventions like vitamin A supplementation during a crucial stage of an infant's life may be beneficial in the long run. There is a need to establish norms for vitamin A levels and seriously examine the role of vitamin A supplementation for LBW babies during the immediate postnatal period.
维生素A在降低6个月以上婴儿死亡率方面的作用已广为人知。在出生后48小时内给新生儿补充维生素A可使婴儿死亡率降低近四分之一，对低出生体重（LBW）婴儿的益处最大。通过客观测量维生素A水平来突出新生儿尤其是低出生体重婴儿的缺乏状态的研究，将有助于制定给这些婴儿补充维生素A的建议。
采用高效液相色谱法（HPLC）分析了154名出生体重在1505 - 2455范围内的低出生体重婴儿的脐血血浆维生素A水平（视黄醇）。还分析了55名出生体重正常婴儿的样本。低出生体重婴儿被分为早产低出生体重和足月低出生体重小于胎龄（SGA）两个亚组。
在154名低出生体重婴儿中，92名是早产低出生体重，52名是足月低出生体重小于胎龄。早产低出生体重组（n = 92）的脐血血浆维生素A平均水平显著低于出生体重正常婴儿（n = 55）和足月低出生体重小于胎龄亚组（n = 62）。出生体重正常婴儿和足月低出生体重小于胎龄组之间的维生素A平均值无显著差异。在整个（n = 154）低出生体重婴儿组中，脐血维生素A水平与出生体重呈显著正相关（r = 0.37，P < 0.0001）。
本研究显示早产低出生体重婴儿的脐血维生素A水平显著较低。低出生体重婴儿的维生素A水平也与其出生体重相关。有足够的证据支持维生素A缺乏状态与新生儿发病率之间的因果关联。在婴儿生命的关键阶段进行简单的干预，如补充维生素A，从长远来看可能有益。有必要建立维生素A水平的规范，并认真研究在出生后立即给低出生体重婴儿补充维生素A的作用。
