The effect of vitamin D supplementation on serum total 25(OH) levels and biochemical markers of skeletal muscles in runners.

What Was Tested

The paper reports a study of Vitamin D, K2, Magnesium and Zinc, published as a randomized controlled trial.

The present study aimed to evaluate the effects of a 3-week vitamin D supplementation on serum 25(OH)D levels and skeletal muscle biomarkers (i.e. troponin, myoglobin, creatine kinase and lactic dehydrogenase) of endurance runners.

All subjects participated in three exercise protocols: (a) incremental exercise test (to determine the maximum oxygen uptake and the intensity of eccentric exercise), (b) eccentric exercise before and (c) after two dietary protocols.

A two-way ANOVA was used to test main effects and their interactions and Pearson correlation coefficients were analyzed to determine the effects of inter-variable relationships.

Who Took Part

By PubMed's age tags, the people studied were adults, men only.

A double-blind placebo-controlled study design was used and vitamin D supplementation was compared to a non-treatment control group.

How the Study Was Run

In design terms this was a randomized, double-blind and placebo-controlled study.

Because people in this Vitamin D, K2, Magnesium and Zinc study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Blinding on both sides kept the participants and researchers unaware of who received Vitamin D, K2, Magnesium and Zinc.

Some participants received a placebo instead of Vitamin D, K2, Magnesium and Zinc, giving a reference point.

Venous blood samples were drawn at rest, immediately after the exercise and after 1 h and 24 h of recovery in order to estimate serum 25(OH)D levels, skeletal muscle biomarkers, proinflammatory cytokines and tumor necrosis factor-alpha (TNF-α) levels.

What Was Measured

Topics PubMed links to this paper include Biomarkers, Muscle, Skeletal, Running, Sports Nutritional Physiological Phenomena and Vitamin D.

Author keywords: Eccentric exercise, Fatigue, Marathon and Muscle biomarkers.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Vitamin D, K2, Magnesium and Zinc.

The abstract goes on to report its results in about 6 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2020 (Journal of the International Society of Sports Nutrition), a journal based in United States.

More context: the Vitamin D, K2, Magnesium and Zinc compound page, all human trials.