Separating fact from artifact in changes in nutrient intake over time.

What Was Tested

The paper reports a study of Magnesium and Iron, published as a randomized controlled trial.

To determine whether the differences between the procedures and nutrient databases used in the 1977-1978 Nationwide Food Consumption Survey (1977-78 NFCS) and those used in the 1987-88 NFCS could notably affect the estimated mean nutrient intakes.

Why It Was Studied

Group A was interviewed using 1987-88 NFCS 24-hour recall procedures and their nutrient intakes were calculated using the 1987-88 NFCS food codes, weight conversion factors, and nutrient database.

Group B was interviewed using 1977-78 NFCS 24-hour recall procedures and nutrient intakes were calculated four ways using various combinations of 1987-88 and 1977-78 NFCS food codes, weight conversions, and nutrient database.

Who Took Part

According to the abstract, 697 women were involved.

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

This was a split-sample field experiment.

Seventy-two area segments were randomly selected; 10 housing units were selected in each segment and randomly assigned to one of two experimental groups.

How the Study Was Run

The researchers set it up as a randomized study.

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

The study took place in the Philadelphia, Pa, metropolitan area.

The subjects were 697 women aged 20 to 49 years.

What Was Measured

The researchers used two-sample, multivariate t tests; univariate t tests; univariate repeated measures analysis of variance; and univariate paired t tests.

The subject headings attached to it are Artifacts, Data Interpretation, Statistical, Databases, Factual, Diet Surveys, Eating, Interviews as Topic and Iron.

What This Means in Plain Language

The paper is a randomized study of Magnesium and Iron in 697 women.

With several hundred people or more, it is a fairly large study for this kind of research.

Its findings take up roughly 5 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 1994 (Journal of the American Dietetic Association), a journal based in United States.

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