Abrahamsen Bo
Odense Patient Data Explorative Network, University of Southern Denmark, Department of Medicine, Holbæk Hospital, Smedelundsgade 60, DK-4300 Holbæk, Odense, Denmark.
Ther Adv Musculoskelet Dis. 2017 May;9(5):107-114. doi: 10.1177/1759720X16685547. Epub 2017 Mar 26.
Areas of the world where vitamin D levels are low for months of the year and intakes of calcium are high have a high prevalence of osteoporosis and cardiovascular disease. This suggests a public health message of avoiding calcium supplements and increasing vitamin D intake. No message could be more welcome as vitamin D can be given as a bolus while calcium must be taken daily and may be poorly tolerated. This approach is based on no evidence from intervention studies. Randomized controlled trials (RCTs) suggest that vitamin D given with calcium elicits a small reduction in fracture risk and deaths. This has not been demonstrated for D given alone. The cardiovascular safety of calcium and vitamin D (CaD) supplements is difficult to ascertain due to weaknesses in RCT designs and adjudication that cannot be remedied by subanalysis. Moreover, no major new RCTs are in process to provide better evidence. It remains unclear that calcium from dietary sources has health advantages over supplements. Benefits may be confined to patients with poor nutritional intake and the small effects at societal levels may be derived from large effects in a small number of patients. This has been impossible to confirm given the limited information about baseline vitamin D and calcium status at entry into trials. Future intervention studies should carefully capture baseline characteristics as these may determine the strength of the response, and make more efficient use of randomization strategies allowing subsequent disassembly or subanalyses while maintaining balancing. Though large clinical RCTs currently evaluate the effects of higher vitamin D doses (equivalent to 50-83 µg/d) there is no current research effort regarding the calcium controversy. In the absence of such studies it is not possible to provide clinicians with evidence-based recommendations regarding the best use of CaD supplementation.
在一年中数月维生素D水平较低且钙摄入量较高的世界某些地区，骨质疏松症和心血管疾病的患病率很高。这表明了一条公共卫生信息，即应避免补充钙并增加维生素D的摄入量。没有比这更受欢迎的信息了，因为维生素D可以一次性大剂量服用，而钙必须每日服用且耐受性可能较差。这种方法没有来自干预研究的证据支持。随机对照试验（RCT）表明，钙与维生素D一起服用可使骨折风险和死亡率略有降低。单独服用维生素D尚未证明有此效果。由于RCT设计和判定存在缺陷，无法通过亚分析加以纠正，因此难以确定钙和维生素D（CaD）补充剂对心血管的安全性。此外，目前没有正在进行的重大新RCT来提供更好的证据。饮食来源的钙是否比补充剂具有健康优势仍不清楚。益处可能仅限于营养摄入不良的患者，而在社会层面的微小影响可能来自少数患者的显著效果。鉴于试验入组时关于基线维生素D和钙状态的信息有限，这一点无法得到证实。未来的干预研究应仔细记录基线特征，因为这些特征可能决定反应的强度，并更有效地利用随机化策略，以便后续进行拆解或亚分析，同时保持平衡。尽管目前大型临床RCT正在评估更高剂量维生素D（相当于50 - 83微克/天）的效果，但目前尚无关于钙争议的研究工作。在缺乏此类研究的情况下，无法为临床医生提供关于最佳使用CaD补充剂的循证建议。
