The same breeding techniques that have been used to boost calcium in carrots could be applied to other crops, say Agricultural Research Service scientists.

The current U.S. recommended average intake of calcium for adults aged 19 to 50 is 1,000 milligrams daily. But inadequate dietary calcium is a global concern, and poor diets and exercise habits prevent many people from achieving and maintaining optimal bone health.

To combat this, Kendal Hirschi, a professor at the Children's Nutrition Research Center in Houston, modified carrots by giving them a gene from the model plant Arabidopsis thaliana that encodes a calcium transporter, according to a news release.

The goal of the research was to induce carrots to express increased levels of the gene sCAX1, which enables transport of calcium across plant cell membranes.

Hirschi and fellow researcher Steve Abrams, say they hope what they've learned with carrots can be applied to other vegetables.

To determine the bioavailability of the calcium in the modified carrots, 30 volunteers—15 females and 15 males of various ethnic backgrounds and in their early to late 20s—ate single meals containing regular or modified carrots, which were labelled with a stable isotope of calcium.

After two weeks, the researchers found that the calcium intake of volunteers who consumed the modified carrots increased by 41 percent, compared to those who ate regular carrots.