Seasonal variations in vitamin D and bone status in in- and outdoor Japanese female athletes

2014 Fiscal Year Final Research Report

• Project/Area Number: 24700626
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Physical education
• Research Institution: Juntendo University
• Principal Investigator: MARUYAMA Asako 順天堂大学, スポーツ健康科学部, 助手 (00420878)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 血中ビタミンD / 季節変動 / 女性 / 骨 / 屋内・屋外

Outline of Final Research Achievements

Vitamin D (VD) insufficiency is a concern, particularly among young Japanese females. VD status shows seasonal variations, since it correlates with duration of sunlight exposure. VD insufficiency in indoor athletes is therefore suggested in winter. The purpose of this study was to determine seasonal variations in VD and bone status among in- and outdoor Japanese female college athletes.
We conducted a prospective cohort study of Japanese female college athletes . Biochemical markers and bone parameters were measured in March, June, September and December. Serum 25-hydroxyvitamin D (25-OH-D) concentration showed a seasonal oscillation, with a nadir in March and a peak in September. The amplitude of oscillation was greater among indoor athletes than among outdoor athletes. The nadir in bone mass measured as speed of sound occurred in June after peaking in December among both indoor and outdoor athletes. The pattern followed 3 months after changes in 25-OH-D.

Free Research Field

健康運動