Calcium absorption varies within the reference range for serum 25-hydroxyvitamin D.

What Was Tested

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

Calcium absorption is generally considered to be impaired under conditions of vitamin D deficiency, but the vitamin D status that fully normalizes absorption is not known for humans.

Who Took Part

By PubMed's age tags, the people studied were middle-aged adults, women only.

Two experiments performed in the spring of the year, one year apart.

Relative calcium absorption at the two 25OHD concentrations was estimated from the area under the curve (AUC) for the load-induced increment in serum total calcium.

How the Study Was Run

In design terms this was a randomized and crossover study.

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

In the crossover set-up each of the participants took both Vitamin D and the comparison in turn, acting as their own control.

A low calcium lunch was provided at mid-day.

What Was Measured

Topics PubMed links to this paper include Area Under Curve, Calcium, Intestinal Absorption, Nutritive Value and Vitamin D.

What This Means in Plain Language

The paper is a randomized and crossover study of Vitamin D and Calcium.

Results are reported in around 5 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2003 (Journal of the American College of Nutrition), a journal based in United States.

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