Nutritive utilization of phosphorus in the rat: influence of intestinal resection and dietary medium chain triglycerides and vitamin D3.

The effects of intestinal resection and diet on the digestive and metabolic utilization of phosphorus were studied in adult rats from which 50% of the distal small intestine had been removed and in sham-operated controls. Metabolic parameters were measured both 1 and 3 months after surgery. The loss of half of the distal small intestine led to a decline in digestive utilization of phosphorus 1 month after surgery as reflected in bone mineral content. Digestive efficiency had improved by 3 months after surgery. One month's feeding with a diet in which fat was provided as equal parts of medium chain triglycerides, sunflower seed oil and olive oil instead of 100% olive oil enhanced phosphorus absorption and retention, although this improvement was less evident after 3 months. The negative effects of distal small intestine resection on the nutritive utilization of phosphorus were not only palliated but significantly enhanced by supplementing the diet with vitamin D3 at a rate of 0.08 mg/100 g diet. This dose is within physiological limits, and favors phosphorus deposition in bone tissue.