From: Vitamin D levels and bone mineral density of middle-aged premenopausal female football and volleyball players in Japan: a cross-sectional study
Non-exercise
Volleyball
Football
P-value b
(n = 25)
(n = 40)
(n = 27)
None
21
25
22
0.14
(84.0) a
(62.5)
(81.5)
Past experience
2
6
4
(8.0)
(15.0)
(14.8)
Yes
9
1
(22.5)
(3.7)