First, apologies if this is more suited for the ‘Supplements and Nutrition’ forum, I am posting here since it is related to Peri-Workout Nutrition.
Attached are 3 studies regarding vitamin D and insulin; I forget the order but essentially but due to these studies I have recently added 2,000 IU vitamin D with my pre-workout nutrition, as it seems that vitamin D helps release AND store insulin in cells in the presence of glucose stimulation.
My question is, does the peri-workout protocol focus on serum levels of insulin (in which vitamin D’s 2 actions would make no significant difference) or produced and utilized levels of insulin?
http://sciencelinks.jp/j-east/article/200022/000020002200A0808361.php
http://joe.endocrinology-journals.org/cgi/content/abstract/160/1/87