ARS | Publication request: Improved bioavailability of calcium in genetically-modified carrots

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: March 3, 2008
Publication Date: May 8, 2008
Citation: Hawthorne, K.M., Morris, J., Hotze, T., Abrams, S.A., Hirschi, K.D. 2008. Improved bioavailability of calcium in genetically-modified carrots [abstract]. Journal of Federation of American Societies for Experimental Biology. 22:1096.5.

Technical Abstract: Osteoporosis is one of the world's most prevalent nutritional disorders, and inadequate absorbed calcium is a known contributor to the pathophysiology of this condition. In a cross-over study of 15 male and 15 female young adults, we used a dual stable isotope method with 42Ca-labeled genetically-modified (sCAX1) and control carrots and intravenous 46Ca to determine the absorption of calcium from these carrots in humans. Subjects also consumed 48Ca-labeled milk for comparison. Calcium absorption efficiency was 42.6 +/– 2.8% and 52.1 +/– 3.2% (p<0.001) for the sCAX1 carrots and control carrots, respectively (all data are Mean +/– SEM); however, total calcium absorption per 100 g of carrots was 41 +/– 2% higher in sCAX1 carrots compared to control carrots (26.50 vs. 15.34 mg Ca/100g, p<0.001). Calcium absorption efficiency from the milk was similar to that from the control carrots (50.1 +/– 3.0% vs. 52.1 +/– 3.2%, p=0.7) but was slightly higher than that from the sCAX1 carrots (50.1 +/– 3.0% vs. 42.6 +/– 2.8%, p<0.05). These results demonstrate the first human study to establish the nutritional consequences of a genetically modified calcium increase in food and support the use of novel approaches to enhance the micronutrient content of vegetables.