Authors: A Zittermann O Sabatschus S Jantzen P Platen A Danz T Dimitriou K Scheld K Klein P Stehle
Publish Date: 2014/03/13
Volume: 67, Issue: 3, Pages: 215-219
Abstract
The effect of physical activity on human calcium Ca metabolism is still not completely understood Thus we investigated fractional Ca absorption using a stable strontium test Fc240 calciotropic hormones and renal Ca excretion in 31 young men with a high activity level GH and in 26 agematched sedentary control subjects GL Weekly hours spent on physical activity obtained with a questionnaire were 150 ± 66 GH and 10 ± 14 GL respectively Serum testosterone levels were significantly lower in GH compared with GL P 0005 Dietary Ca intake 4day food record was twice as high in GH compared with GL men P 0001 GH had significantly higher serum calcitriol levels and Fc240 values than GL P 0001 and P 001 respectively In a stepwise multiple regression analysis including serum levels of 25hydroxyvitamin D calcitriol testosterone and dietary Ca intake only calcitriol was significantly correlated with Fc240 P= 0017 Twentyfour hour renal Ca excretion was only slightly higher in GH compared with GL P 005 However additional Ca losses might have occurred through the extensive sweating of GH as indicated by a difference of 17 liter between fluid intake and renal fluid excretion P 0001 In summary we observed a higher fractional Ca absorption rate in physically active young men compared with sedentary controls which is probably mediated by calcitriol The low testosterone serum levels of the athletes were obviously not a limiting factor in Ca absorption efficiency An additional Ca retention might however only be obtained if absorbed Ca exceeded total obligatory Ca losses
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