Overlapping vitamin A interventions with provitamin A carotenoids and preformed vitamin A fortificant cause high liver retinol stores in male mongolian gerbils

Authors: SOWA, MARGARET - University Of Wisconsin; MOURAO, LUCIANA - University Of Wisconsin; SHEFTEL, JESSE - University Of Wisconsin; KAEPPLER, MIKAYLA - University Of Wisconsin; SIMONS, GABRIELLE - University Of Wisconsin; DAVIS, CHRISTOPHER - University Of Wisconsin; Simon, Philipp; PIXLEY, KEVIN - International Maize & Wheat Improvement Center (CIMMYT); TANUMIHARDJO, SHERRY - University Of Wisconsin

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2020
Publication Date: 5/26/2020
Citation: Sowa, M., Mourao, L., Sheftel, J., Kaeppler, M., Simons, G., Davis, C.R., Simon, P.W., Pixley, K.V., Tanumihardjo, S.A. 2020. Overlapping vitamin A interventions with provitamin A carotenoids and preformed vitamin A fortificant cause high liver retinol stores in male mongolian gerbils. Journal of Nutrition. 150(11):2912-2923. https://doi.org/10.1093/jn/nxaa142.
DOI: https://doi.org/10.1093/jn/nxaa142

Interpretive Summary: With vitamin A deficiency continuing to be a significant health problem in some developing countries, people in those regions may be receiving vitamin A pills from healthcare workers, as well as eating vegetables like carrots or orange maize which also provide vitamin A in the orange pigments they contain. To determine in the combination of vitamin A from pills combined with these food sources might result in excessive vitamin A nutrition, this study fed gerbils diets varying in sources of vitamin A. The carrots or orange maize by themselves provided adequate vitamin A without the need for more from pills. When gerbils were fed both the plant sources of vitamin A as well as preformed vitamin A from pills, vitamin A levels were higher than recommended, indicating that healthcare workers may need to determine if children they dose with vitamin A are actually getting a dietary source. This research is of interest to nutritionists, and to healthcare workers in developing countries.

Technical Abstract: Background: Vitamin A (VA) deficiency is a public health problem in some African countries. Food fortification, supplementation, and increased provitamin A consumption through biofortification are effective strategies but monitoring is needed due to risk for excessive VA intake with multiple interventions targeting the same groups. High liver VA stores were determined in Zambian children exposed to overlapping VA programs. Objectives: Two studies in Mongolian gerbils simulated the condition of exposure to multiple VA interventions. The effects of provitamin A consumption from biofortified orange maize and carrots, and VA consumption from preformed VA fortificant on VA status were investigated. Methods: Study 1 was a 2x2x2 factorial (n = 85) with biofortified high-beta-carotene maize, orange carrots, and VA fortification at 50% estimated gerbil needs, compared with white maize and carrot VA-free controls. Study 2 was a 2x3 factorial (n = 66) evaluating the effects of orange carrot and excessive VA consumption through fortification at 100 and 200% of estimated needs. Both studies utilized a 2-wk VA-depletion phase, baseline evaluation, 9-wk treatment phase, and determined VA status with liver stores by HPLC. Results: In Study 1, orange carrot and orange maize groups liver retinol concentrations were significantly higher than baseline and controls. VA+ fortificant alone did not significantly improve VA status. In Study 2, orange carrot addition to feeds significantly enhanced liver stores relative to baseline, but VA fortificant alone did not. Serum retinol concentrations did not differ among groups in either study. Conclusions: Orange carrots and biofortified maize prevented VA deficiency as single interventions. On the background of adequate dietary intake of provitamin A carotenoids from carrots, VA fortification caused excessive and hypervitaminotic liver stores in this animal model.