ビタミンDの身体機能への効果

ビタミンDの身体機能への効果を見た研究の系統的レビュー論文を紹介します。

C. ANNWEILER, A.M. SCHOTT, G. BERRUT, B. FANTINO, O. BEAUCHET: VITAMIN D-RELATED CHANGES IN PHYSICAL PERFORMANCE: A SYSTEMATIC REVIEW. The Journal of Nutrition, Health & Aging©
Volume 13, Number 10, 893-898, 2009

2004年から2008年の論文で、ビタミンDの筋肉、バランス、歩行への効果を高齢者で評価したものをまとめています。多くは地域在住の高齢女性が対象です。

結果としては、筋肉、バランス、歩行のいずれも有効という報告と無効という報告があり、現時点では結論を出せる状況ではないとのことです。今回はメタ分析は実施されていません。

転倒予防に関してはビタミンDが有効な可能性がありますが（コクランの系統的レビューでは無効とされていますが、その他の系統的レビューでは有効とされています）、身体機能の改善に関してはまだどちらともいえないというところです。

そのため、身体機能改善を目的としたビタミンDの使用は、ビタミンDが欠乏している患者に限定されると思います。ビタミンDが不足している患者にルーチンに使用するほどのエビデンスはないと考えます。

Abstract

Objective: The objective of this study was to systematically review all the published articles examining the effects of low serum vitamin D concentration and vitamin D supplementation on muscle, balance and gait performance among people aged 65 and older.

Methods: An English and French Medline search ranging from January 2004 to November 2008 indexed under the Medical Subject Heading (MeSH) terms "aged OR aged, 80 and over" AND "Vitamin D OR Vitamin D Deficiency" combined with the terms "Gait" OR "Gait Apraxia" OR "Gait Disorders, Neurologic" OR "Walking" OR "Mobility Limitation" OR "Polyneuropathy" OR "Proprioception" OR "Ataxia" OR "Accidental Falls" was performed.

Results: Of the 102 selected studies, 16 met the selection criteria and were included in the final analysis. There were 8 observational studies and 8 interventional studies. The number of participants ranged from 24 to 33067. A majority of studies examined community-dwelling older women. Five observational studies showed a significant positive association, whereas three studies did not. Four of the 5 studies and two of the 3 studies which tested the vitamin D supplementation effect, respectively on balance and gait, showed no significant effect. Four studies showed a significant effect on muscle strength, while this effect was not observed in three others studies. In addition, there was no significant association between vitamin D supplementation and an improvement of the sit-to-stand test results in 50% of the studies.

Conclusions: The findings show that the association between vitamin D and physical performance remains controversial. Observational studies and clinical trials yielded divergent results, which highlights the complex and to date still poorly understood association between serum vitamin D concentration or vitamin D supplementation and physical performance.