Institute for Integrated Sports Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
J Bone Miner Metab. 2010 Sep;28(5):540-6. doi: 10.1007/s00774-010-0158-3. Epub 2010 Feb 18.
The objective of the present study was to investigate the nutritional status from the aspect of bone metabolism in Japanese elite male athletes with increased bone resorption. Urinary levels of a bone resorption marker, cross-linked N-terminal telopeptide of type 1 collagen (NTX), were measured in 71 professional baseball players (age, 18-39 years); the mean urinary NTX level was 65.6 (range, 17.5-269.0) nM BCE/mM Cr. Of 71 athletes, 9 with high levels of urinary NTX (greater than mean + 1 SD) were examined by measuring serum biochemical markers and nutritional assessment (simple food frequency questionnaire). Serum biochemical marker analysis showed that 7 of these 9 athletes had vitamin D insufficiency, as indicated by low serum levels of 25-hydroxyvitamin D, and that all 9 athletes showed vitamin K insufficiency as indicated by low levels of vitamins K(1) and K(2). Nutritional assessment revealed high intakes of protein and low intakes of calcium and vitamin D based on adequate intake (AI). However, daily vitamin K intake achieved the AI. These results suggest that there exist elite male athletes who show increased bone resorption and calcium and vitamin D insufficiency. However, there was a discrepancy between vitamin K intake and serum levels of vitamins K(1) and K(2). The present study raised an issue regarding the nutritional status from the point of view of bone metabolism in elite male athletes such as professional baseball players.
本研究旨在探讨日本男性精英运动员骨代谢方面的营养状况。我们对 71 名职业棒球运动员（年龄 18-39 岁）进行了骨吸收标志物——1 型胶原交联 N 末端肽（NTX）的尿水平检测，其平均尿 NTX 水平为 65.6（范围 17.5-269.0）nM BCE/mM Cr。在这 71 名运动员中，9 名尿 NTX 水平较高（高于均数+1SD）的运动员接受了血清生化标志物和营养评估（简单食物频率问卷）检查。血清生化标志物分析显示，这 9 名运动员中有 7 人维生素 D 不足，表现为血清 25-羟维生素 D 水平低，所有 9 名运动员均表现为维生素 K 不足，表现为维生素 K(1)和 K(2)水平低。营养评估显示，根据适宜摄入量（AI），这些运动员的蛋白质摄入量较高，而钙和维生素 D 的摄入量较低。然而，每日维生素 K 的摄入量达到了 AI。这些结果表明，存在一些骨吸收增加、钙和维生素 D 不足的男性精英运动员。然而，维生素 K 的摄入量与血清中维生素 K(1)和 K(2)的水平存在差异。本研究从男性精英运动员（如职业棒球运动员）骨代谢的角度提出了一个营养状况的问题。
