Fig. 3From: Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men? – a randomized controlled trialSerum 25(OH)D concentrations. Mean serum 25(OH)D concentrations ± SEM for young and elderly vitamin-D and placebo groups. Week 0 denote start of training period. # different from placebo (p < 0.05). $ different from week −4 (p < 0.05). () denote tendency (0.05 < p < 0.10)Back to article page