Cashman Kevin D, Hayes Aoife, O'Donovan Sinead M, Zhang Joy Y, Kinsella Michael, Galvin Karen, Kiely Mairead, Seamans Kelly M
From the School of Food and Nutritional Sciences (KMS, AH, SMO, JYZ, M Kinsella, KG, M Kiely, and KDC) and the Department of Medicine (KDC), University College Cork, Cork, Ireland.
Am J Clin Nutr. 2014 Jun;99(6):1414-23. doi: 10.3945/ajcn.113.080358. Epub 2014 Apr 2.
Interactions between calcium and vitamin D may have implications for the regulation of serum 25-hydroxyvitamin D [25(OH)D] and its catabolism and, consequently, the vitamin D dietary requirement.
We investigated whether different calcium intakes influenced serum 25(OH)D and indexes of vitamin D activation and catabolism during winter and in the context of both adequate and inadequate vitamin D intakes.
A 15-wk winter-based, randomized, placebo-controlled, double-blind vitamin D₃ intervention (20 μg/d) study was carried out in free-living men and women aged ≥50 y (n = 125) who were stratified according to calcium intakes [moderate-low (<700 mg/d) or high (>1000 mg/d) intake]. The serum 25(OH)D concentration was the primary outcome, and serum calcium, parathyroid hormone (PTH), 1,25-dihydroxyvitamin D [1,25(OH)₂D], 24,25-dihydroxyvitamin D [24,25(OH)₂D], the ratio of 24,25(OH)₂D to 25(OH)D, vitamin D-binding protein, and free 25(OH)D were exploratory outcomes.
A repeated-measures ANOVA showed there was no significant (P = 0.2) time × vitamin D treatment × calcium intake grouping interaction effect on the mean serum 25(OH)D concentration over the 15-wk intervention period. Serum 25(OH)D concentrations increased (P ≤ 0.005) and decreased (P ≤ 0.002) in vitamin D₃ and placebo groups, respectively, and were of similar magnitudes in subjects with calcium intakes <700 mg/d (and even <550 mg/d) compared with >1000 mg/d. The response of serum PTH, 1,25(OH)₂D, 24,25(OH)₂D, the ratio of 24,25(OH)₂D to 25(OH)D, and free 25(OH)D significantly differed in vitamin D₃ and placebo groups but not by calcium intake grouping.
We found no evidence of a vitamin D sparing effect of high calcium intake, which has been referred to by some authors as "vitamin D economy." Thus, recent dietary vitamin D requirement estimates will cover the vitamin D needs of even those individuals who have inadequate calcium intakes.
钙与维生素D之间的相互作用可能对血清25-羟基维生素D [25(OH)D] 的调节及其分解代谢有影响，进而影响维生素D的膳食需求量。
我们研究了在冬季以及维生素D摄入充足和不足的情况下，不同钙摄入量是否会影响血清25(OH)D以及维生素D激活和分解代谢指标。
在年龄≥50岁的自由生活男性和女性（n = 125）中开展了一项为期15周的基于冬季的随机、安慰剂对照、双盲维生素D₃干预（20 μg/d）研究，这些受试者根据钙摄入量[中低（<700 mg/d）或高（>1000 mg/d）摄入量]进行分层。血清25(OH)D浓度是主要结局指标，血清钙、甲状旁腺激素（PTH）、1,25-二羟基维生素D [1,25(OH)₂D]、24,25-二羟基维生素D [24,25(OH)₂D]、24,25(OH)₂D与25(OH)D的比值、维生素D结合蛋白和游离25(OH)D是探索性结局指标。
重复测量方差分析显示，在15周的干预期内，时间×维生素D治疗×钙摄入分组交互作用对平均血清25(OH)D浓度无显著（P = 0.2）影响。维生素D₃组和安慰剂组的血清25(OH)D浓度分别升高（P≤0.005）和降低（P≤0.002），与钙摄入量>1000 mg/d的受试者相比，钙摄入量<700 mg/d（甚至<550 mg/d）的受试者中变化幅度相似。维生素D₃组和安慰剂组中血清PTH、1,25(OH)₂D、24,25(OH)₂D、24,25(OH)₂D与25(OH)D的比值以及游离25(OH)D的反应存在显著差异，但不受钙摄入分组的影响。
我们没有发现高钙摄入具有维生素D节约效应的证据，一些作者将其称为“维生素D经济”。因此，最近对膳食维生素D需求量的估计将涵盖即使钙摄入量不足的个体的维生素D需求。
