Dietary calcium does not interact with vitamin D₃ in terms of determining the response and catabolism of serum 25-hydroxyvitamin D during winter in older adults.

What Was Tested

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

The researchers investigated whether different calcium intakes influenced serum 25(OH)D and indexes of vitamin D activation and catabolism during winter and in the context of both adequate and inadequate vitamin D intakes.

Why It Was Studied

Interactions between calcium and vitamin D may have implications for the regulation of serum 25-hydroxyvitamin D [25(OH)D] and its catabolism and, consequently, the vitamin D dietary requirement.

Who Took Part

By PubMed's age tags, the people studied were middle-aged adults, older adults and people over 80, both men and women.

How the Study Was Run

The design is described as randomized, double-blind and placebo-controlled.

Random assignment meant chance, not the researchers, decided who got Vitamin D, K2, Magnesium and Zinc and who got the comparison, which limits bias.

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

A placebo (an inactive look-alike) gave the Vitamin D, K2, Magnesium and Zinc group a baseline to be compared against.

The serum 25(OH)D concentration was the primary outcome, and serum calcium, parathyroid hormone (PTH), 1,25-dihydroxyvitamin D [1,25(OH)₂D], 24,25-dihydroxyvitamin D [24,25(OH)₂D], the ratio of 24,25(OH)₂D to 25(OH)D, vitamin D-binding protein, and free 25(OH)D were exploratory outcomes.

What Was Measured

PubMed files the paper under topics including 24,25-Dihydroxyvitamin D 3, 25-Hydroxyvitamin D 2, Aging, Calcifediol, Calcitriol, Calcium and Calcium, Dietary.

What This Means in Plain Language

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

Its findings take up roughly 4 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2014 (The American journal of clinical nutrition), a journal based in United States.

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