JCEM：维生素D3和钙强化的乳制品能更好的预防骨吸收

对伴有维生素D缺乏、继发性甲状旁腺功能亢进、骨吸收增加和骨质疏松性骨折风险的缺乏自理能力的老年女性，使用强化食品对骨退化进行营养预防似乎是非常合适的。为了评估在老年女性，维生素D和钙的强化酸奶与相同热量和蛋白质的乳制品相比，是否能对血清甲状旁腺激素（PTH）和骨吸收标记物（BRM）发挥额外的降低效果，来自瑞士日内瓦大学医院的Jean Philippe Bonjour教授及其团队进行了一项研究，该研究发现在骨质疏松性骨折高危的缺乏自理能力的老年女性，维生素D₃和钙强化的乳制品与非强化的等价食物相比，能更好的预防骨吸收加速。该研究结果在线发表在2013年5月7日的美国《临床内分泌代谢杂志》（The journal of clinical endocrinology & metabolism）上。

该研究是一项随机双盲对照试验，在缺乏自理能力的女性（平均年龄85.5岁）进行56天干预，消耗两种125g食物种任何一种，维生素D和钙强化酸奶（FY），每天补充10ug维生素D₃和800mg钙，或者非强化对照酸奶（CY），每天提供280mg钙。终点是从基线（DO）到D28和D56，血清25–羟维生素–D（25OHD）、PTH和BRM的变化：主要观察指标是抗酒石酸酸性磷酸酶5b（TRAP5b），次要观察指标是I型胶原羧基末端肽（CTX）。

该研究结果表明，在D56，血清25OHD在FY（29例）和CY（27例）分别增加（均数±标准误）25.3±1.8nmol/l vs5.2±2.5nmol/l（P＜0.0001）。在FY和CY，PTH相应的改变分别为－28.6±7.2 vs－8.0±4.3%（P=0.0003），TRAP5b分别为－21.9±4.3 vs 3.0±3.2%（P＜0.0001），CTX分别为－11.0±9.7 vs－3.0±4.1%（P=0.0146）。在D28，这些差异没那么明显，但在25OHD、PTH和TRAP5b已经有意义。

该研究发现，在骨质疏松性骨折高危的缺乏自理能力的老年女性，维生素D₃和钙强化的乳制品与非强化的等价食物相比，能更好的预防骨吸收加速。

Consumption of yogurts fortified in vitamin D and calcium reduces serum parathyroid hormone and markers of bone resorption: a double-blind randomized controlled trial in institutionalized elderly women.
Abstract
Context:Nutritional prevention of bone deterioration with fortified foods seems particularly suitable in institutionalized elderly women at risk of vitamin D deficiency, secondary hyperparathyroidism, increased bone resorption and osteoporotic fracture.Objective:To evaluate whether fortification of yogurts with vitamin D and calcium exerts an additional lowering effect on serum parathyroid hormone (PTH) and bone resorption markers (BRM) as compared to iso-caloric and iso-protein dairy products in elderly women.Design:A randomized double-blind controlled trial, 56-d intervention was conducted in institutionalized women (mean age 85.5 yr) consuming two 125 g servings of either vitamin D and calcium-fortified yogurts (FY) at supplemental levels of 10 μg vitamin D3/d and calcium 800 mg/d, or non fortified control yogurts (CY) providing 280 mg/d of calcium.Main Outcomes:The endpoints were serum changes from baseline (D0) to D28 and D56 in 25-hydroxyvitamin-D (25OHD), PTH and in BRM: Tartrate-resistant-acid-phosphatase-isoform-5b (TRAP5b), the primary outcome, and carboxy-terminal-cross-linked-telopeptide of type-I-collagen (CTX).Results:At D56, serum 25OHD increased (mean±SEM) by 25.3±1.8 vs. 5.2±2.5 nmol/L in FY (n=29) and CY (n=27), respectively (P<0.0001). The corresponding changes in PTH were -28.6±7.2 vs. -8.0±4.3% (P=0.0003), TRAP5b -21.9±4.3 vs. 3.0±3.2% (P<0.0001), CTX -11.0±9.7 vs. -3.0±4.1% (P=0.0146), in FY and CY, respectively. At D28, these differences were less pronounced, but already significant for 25OHD, PTH and TRAP5b.Conclusions:This study in institutionalized elderly at high risk for osteoporotic fracture suggests that fortification of dairy products with vitamin D3 and calcium provides a greater prevention of accelerated bone resorption as compared to non-fortified equivalent foods.