Wolf H, Kerstan B, Kerstan J
Klin Padiatr. 1975 Jul;187(4):331-41.
The necessary daily amount of vitamin D3 in premature infants was calculated by Hövels and his group as being 25 mcg (1000 I.U.). This was in agreement with our own investigations. Without vitamin D3, however, the incidence of rikkets in premature and small-for-dates newborns occurred usually at the beginning of the second month of life. Clinical signs of rickets are still absent at this time, while an increased activity of the serum alkaline phosphatase signals the beginning of the illness. Three groups of prematurely born infants received up to 50 days daily oral doses of 12.5 mcg vitamin D3 (=500 I.U.), 25 mcg vitamin D3 (=1000 I.U.) or 9 mcg 25-hydroxycholecalciferol (25-HCC), respectively, while one untreated group served as control. No differences were noted between the four groups in the serum values of calcium and phosphorus. The activity of the alkaline phosphatase tended to be higher in the untreated and the 500 I.U. groups. The differences were prouved by the chi2-test to be significant (see table 2 and 3). It appeared that 9 mcg of 25-HCC prevented the rise in alkaline phosphatase slightly better than 25 mcg of vitamin D3 (1000 I.U.). On a mcg base 25-HCC seems three times as effective as cholecalciferol. One could speculate about a delayed hydroxylation of cholecalciferol (vitamin D3) to 25-HCC.
赫韦尔斯及其团队计算出早产儿每日所需的维生素D3量为25微克（1000国际单位）。这与我们自己的研究结果一致。然而，在没有维生素D3的情况下，早产儿和小样儿新生儿通常在出生后第二个月开始出现佝偻病发病率。此时佝偻病的临床症状仍然不存在，而血清碱性磷酸酶活性增加则预示着疾病的开始。三组早产婴儿分别接受了长达50天的每日口服剂量的12.5微克维生素D3（=500国际单位）、25微克维生素D3（=1000国际单位）或9微克25-羟胆钙化醇（25-HCC），而一个未治疗组作为对照。四组在血清钙和磷值方面没有差异。碱性磷酸酶的活性在未治疗组和500国际单位组中往往较高。经卡方检验证明差异具有显著性（见表2和3）。看来9微克的25-HCC预防碱性磷酸酶升高的效果略优于25微克的维生素D3（1000国际单位）。以微克为基础计算，25-HCC的效果似乎是胆钙化醇的三倍。人们可以推测胆钙化醇（维生素D3）向25-HCC的羟基化过程存在延迟。
