CALCIUM AND VITAMIN D2 ABSORPTION AND EFFECT ON NITROGEN UTILIZATION OF MILK

Micronutrient fortified milk was developed and its bioavailability using in-vivo (rats) and in-vitro gastrointestinal simulated method was determined. In in-vivo studies, rats fed with fortified milk powders and its effect on nitrogen utilization indices were determined. Results showed that both calcium citrate and calcium phosphate showed similar absorption in all treatment groups viz. calcium, vitamin D2 and calcium+vitamin D2 groups. Vitamin D increased calcium absorption when fortified singly and in combination with both calcium salts. The weight of rats increased after every interval of week in comparison to day 0. The calcium and vitamin D fortified group showed significantly (p<0.05) highest protein efficiency ratio followed by vitamin D fortified group, calcium fortified group and control. Similar trend observed in net protein utilization and digestibility coefficient, however, both nutrient fortified group showed significantly (p<0.05) higher biological value than other three groups. Vitamin D has positive effect on protein digestibility indices; calcium has no or slight effect, whereas, when fortified in combination rats showed higher nitrogen utilization.