Vitamin D Supplementation Has No Impact on Cardiorespiratory Fitness, but Improves Inflammatory Status in Vitamin D Deficient Young Men Engaged in Resistance Training

• Published in: Nutrients 2022-12, Vol.14 (24), p.5302
• Main Authors: Savolainen, Lauri, Timpmann, Saima, Mooses, Martin, Medijainen, Luule, Tõnutare, Lisette, Ross, Frederik, Lellsaar, Märt, Piir, Anneli, Zilmer, Mihkel, Unt, Eve, Ööpik, Vahur
• Format: Article
• Language: English
• Subjects: Alfacalcidol; Calcifediol; Calciferol; Cardiorespiratory Fitness; Cholecalciferol; Chronic illnesses; Dietary Supplements; Double-Blind Method; Ergocalciferols - therapeutic use; Ethylenediaminetetraacetic acid; Hemoglobin; Heterogeneity; Humans; Hypotheses; Inflammation; Interleukin 10; Male; Muscles; Musculoskeletal system; Oxygen consumption; Physical fitness; Physical training; Resistance Training; Strength training; Tumor necrosis factor; Tumors; Vitamin D; Vitamin D Deficiency - drug therapy; Vitamins; Weight training
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu14245302

Data on the effect of vitamin D (Vit-D) supplementation on cardiorespiratory fitness (VO2max) are conflicting. A possible source of discrepancies in the literature is the heterogeneity in baseline Vit-D status among participants in previous studies. The main objectives of the present study were to assess the impact of Vit-D supplementation on VO2max and inflammatory status in Vit-D deficient young healthy men. Participants (n = 39, baseline serum Vit-D level < 50 nmol/L) were quasi-randomly assigned to one of the two groups, which, in a double-blind manner, supplemented their diet daily with either Vit-D (8000 IU; VD) or placebo (PLC) and concomitantly performed a 12-week supervised resistance training program. During the 12-week intervention, serum Vit-D concentrations increased 3.9-fold (p < 0.001) in the VD group while no changes occurred in the PLC group. Baseline VO2max did not differ in the two groups and remained unchanged during the intervention. Serum interleukin-10/tumour necrosis factor alpha ratio increased significantly (30%, p = 0.007; effect size 0.399) in VD but not in PLC group. In conclusion, 12-week Vit-D supplementation increases serum 25(OH)D levels and improves inflammatory status, but has no impact on VO2max in Vit-D deficient young men engaged in resistance training.