Ingestion of difructose anhydride III partially restores calcium absorption impaired by vitamin D and estrogen deficiency in rats

Vitamin D (VD) and estrogen deficiencies impair Ca absorption and bone mineralization, and the relevance of the interaction between these factors has not been fully understood. The aim of the present study was to clarify the effects of a nondigestible saccharide, difructose anhydride III (DFAIII), on the interaction of VD and estrogen deficiencies involved in Ca malabsorption by assessing changes in intestinal Ca absorption and bone mineralization by feeding of DFAIII in rats with VD or estrogen deficiency or with a combined loss of VD and estrogen. Three-week-old female Sprague-Dawley rats were divided into four groups: two groups were ovariectomized (OVX) and two were laparotomized (sham). One group each of OVX and sham rats were fed an AIN93G-based normal diet, and the other groups were fed a VD-deficient diet for 8-weeks. Rats from the four groups were divided into two subgroups and fed the normal or VD-deficient diet with or without DFAIII for next 4-weeks. VD deficiency decreased Ca absorption and bone mineralization with reductions in duodenal calbindin D9k mRNA and serum Ca levels. There were no additional reductions in these parameters in the OVX. The reductions in Ca absorption and femoral Ca were restored partially or fully by DFAIII. Recovery of Ca absorption rate by DFAIII was greater in the OVX than in the sham showing an interaction between OVX and VD deficiency in, at least, the DFAIII-fed groups. The cecal pH was lower and the level of short-chain fatty acids in the cecal contents was higher in all the DFAIII groups than those in the control groups. VD deficiency impaired Ca absorption and bone mineralization, and feeding DFAIII partially restored Ca malabsorption and fully recovered bone Ca in VD-deficient rats. No additional reductions in these parameters with a combination of VD deficiency and OVX were noted. However, interactions were found between these factors in the DFAIII-induced increase in Ca absorption.