Vitamin D levels and bone mineral density of middle-aged premenopausal female football players: A cross-sectional study

BACKGROUND: The number of football teams in senior categories has increased. As
outdoor sports entail players being exposed to sunlight, playing football may
contribute to maintaining vitamin D stores and body mineral density while
preventing osteoporosis. This study aimed to determine the bone mineral density
and vitamin D levels in middle-aged premenopausal female football players.
METHODS: Participants were premenopausal females in their 40s. We evaluated bone
mineral density of the second to the fourth lumbar vertebrae and femoral neck,
serum 25-hydroxy vitamin D (25-OHD) levels, which is an indicator of vitamin D
stores, and body composition. In addition, we administered a questionnaire
survey on exercise habits and lifestyle. Ninety-two participants were
categorised into three groups: the football group (n = 27), volleyball group
(n = 40), and non-exercise group (n = 25).
RESULTS: Bone mineral density was higher in the football and volleyball groups
than in the non-exercise group (P < 0.01). The volleyball group had a significantly higher bone mineral density of the lumbar spine and femoral neck than the non-exercise group (P < 0.01). The football group had a significantly higher bone mineral density of the femoral neck than the non-exercise group (P < 0.01). Although the football group had played fewer years than the volleyball group (P < 0.01), serum 25-OHD levels were the highest in the football group and were significantly higher than those in the volleyball and non-exercise groups (P < 0.01). CONCLUSIONS: Middle-aged premenopausal football players had higher body vitamin D levels and bone mineral densities than non-active females. These results suggest that playing football may contribute to the prevention of osteoporosis. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000054235. 2024/04/23. Retrospectively registered. © 2024. The Author(s). DOI: 10.1186/s13102-024-00938-x PMCID: PMC11221148 PMID: 38956731 Conflict of interest statement: The study was conducted under a contract research agreement between Juntendo University and the Japan Football Association. MY received a research grant from the Japan Football Association to conduct this study. The other authors declare that they have no conflicts of interest to disclose.