Mayo Medical School, Rochester, MN, USA.
Bone. 2013 Jul;55(1):64-8. doi: 10.1016/j.bone.2013.03.017. Epub 2013 Apr 6.
Nigerian toddlers with low dietary calcium intakes increased forearm bone mineral density (BMD) after 18 months of calcium supplementation compared with placebo. However, it is not known if this bone mineral accretion is sustained after calcium supplement withdrawal. We therefore investigated the influence of prior calcium supplementation on forearm BMD 12 months after withdrawal of the supplement.
Nigerian toddlers aged 12-18 months from three urban communities were enrolled in a controlled trial of calcium supplementation. Two communities received daily calcium supplements, one as calcium carbonate (400mg), and the other as ground fish (529±109 mg), for a duration of 18 months, and all three communities received vitamin A (2500 IU daily) as placebo. Forearm BMD was measured 5 times during 18 months of calcium supplementation and at 12 months after supplement withdrawal.
Of 647 children enrolled, 390 completed the trial of calcium supplementation and 261 of these returned for the final follow-up 12 months after discontinuation of supplementation. During the 18 months of supplementation, an adjusted model demonstrated that the increase in both distal and proximal forearm BMD over time was significantly greater in the calcium supplemented groups than in the placebo group (P<0.04). However, after supplement withdrawal, the increase in BMD over time was largely attenuated and only remained significant at the proximal forearm in the ground fish group (P=0.03).
The benefit of calcium supplementation on forearm BMD in young Nigerian children is not sustained after supplement withdrawal.
在补充钙 18 个月后，尼日利亚低膳食钙摄入的幼儿前臂骨矿物质密度（BMD）增加，与安慰剂相比。然而，尚不清楚这种骨矿物质积累是否在钙补充剂停药后持续存在。因此，我们研究了在补充剂停药 12 个月后，先前补钙对前臂 BMD 的影响。
来自三个城市社区的 12-18 个月大的尼日利亚幼儿参加了补钙的对照试验。两个社区每天服用钙补充剂，一种是碳酸钙（400mg），另一种是磨碎的鱼（529±109mg），持续 18 个月，所有三个社区都服用维生素 A（每天 2500IU）作为安慰剂。在 18 个月的钙补充期间和补充停止后 12 个月，5 次测量前臂 BMD。
在 647 名入组儿童中，有 390 名完成了钙补充试验，其中 261 名返回参加了最后一次随访，即补充停止后 12 个月。在补充的 18 个月期间，调整后的模型表明，补充钙组的远端和近端前臂 BMD 随时间的增加明显大于安慰剂组（P<0.04）。然而，在补充停止后，BMD 的随时间增加在很大程度上减弱，仅在磨碎的鱼组的近端前臂仍保持显著（P=0.03）。
在尼日利亚幼儿中，钙补充对前臂 BMD 的益处在补充停止后并不持久。
