How vitamin D helps exercise (IGF) – RCT
Vitamin D supplementation affects the IGF system in men after acute exercise.
Growth Horm IGF Res. 2016 Nov 5;30-31:45-51. doi: 10.1016/j.ghir.2016.11.002. [Epub ahead of print]
Darr RL1, Savage KJ2, Baker M3, Wilding GE4, Raswalsky A5, Rideout T6, Browne RW7, Horvath PJ8.
1Department of Kinesiology, Saginaw Valley State University, University Center, GN205 7400 Bay Rd. University Center, MI 48710, USA; Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA. rldarr@svsu.edu.
2Department of Biology, St. John Fisher College, ISHS 212 3690 East Avenue, Rochester, NY 14618, USA. ksavage@sjfc.edu.
3Department of Biostatistics, University at Buffalo, B1148 Center for Tomorrow, Amherst, Buffalo, NY 14260, USA. markbake@buffalo.edu.
4Department of Biostatistics, University at Buffalo, B1148 Center for Tomorrow, Amherst, Buffalo, NY 14260, USA. gwilding@buffalo.edu.
5Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main St. Buffalo, NY 14214, USA. ajr24@buffalo.edu.
6Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main St. Buffalo, NY 14214, USA. rideout@buffalo.edu.
7Department of Biotechnical and Clinical Laboratory Sciences, University at Buffalo, 26 Cary Hall, Buffalo, NY 14214, rwbrowne@buffalo.edu.
8Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA. phorvath@buffalo.edu.
OBJECTIVE:
Contradictory data between the Insulin-Like Growth Factor System (IGF) system and exercise may be due to alteration in IGF binding proteins.
Vitamin D (D) deficiency has been related to muscle weakness and Insulin Like Growth Factor Binding Protein 3 (IGFBP3). A Vit. D and acute exercise merge is proposed to modify the IGF system.
DESIGN:
D insufficient and deficient men (39.0±8.6yo with serum D (25OH D) 20.0±7.7ng/mL) did 1 hour of
stretching (ST),
aerobic (AB), and
resistance (RT) exercises,
before and after 28d of 4000IU/d Vit. D3 (D, n=6) or Placebo (P, n=7).
ST, a time/attention control visit, interchanged unreceptive movements.
AB was moderate intensity treadmill walking.
RT rotated moderate strength 50% 1-RM repetitions (15, 10) of squat, bench press, leg press, and lat pull down.
Serum Total IGF1 (TIGF1), Insulin Like Growth Factor Binding Protein 1 (IGFBP1), and IGFBP3 were measured before (T1, fasting), immediately after (T2), and 2h post (T3) exercise.
RESULTS:
After ST, IGFBP3 was greater in the D group at T2 (2948, 2130ng/mL; p<0.03) and T3 (3087, 2212; p<0.02). During RT, TIGF1 decreased in the Placebo (P) group from T1 to T3 (151.4, 107.3ng/mL; p<0.05), while IGFBP1 increased in the D group from T1 to T3 (26.5, 96.2ng/mL; p<0.05). RT IGFBP3 was greater at T1, T2, and T3 in the D group (2932.5, 2110.7; p<0.03), (3163.9, 2392.5; p<0.04), and (3355.3, 2353.1; p<0.01). In AB, IGFBP3 was greater in the D group at T2 (3128.6, 2226.3.0; p<0.04) and T3 (2949.7, 2135.1; p<0.05).
CONCLUSION:
D supplementation amplified IGFBP3 after low or moderate activity which may increase the delivery of IGF1 to tissues. Resistance exercise with D not only increased IGFBP3 and IGFBP1 levels but also conserved TIGF1 levels, possibly shifting the IGF system for enriched muscle well-being.
PMID: 27863277 DOI: 10.1016/j.ghir.2016.11.002 publisher wants $36 for the PDF