Dietary 25-hydroxyvitamin Deffects on vitamin D status, plasma metabolites and urine mineral excretion in adult cats.

Abstract

OBJECTIVES: The study aimed to evaluate the safety and effectiveness of vitamin D supplementation with dietary 25-hydroxyvitamin D(25[OH]D) in adult cats. METHODS: Three levels of dietary 25(OH)Dconcentrations (4.9, 8.4, 11.8 µg/kg as fed) were received by five adult cats for 9 weeks, each in a randomized complete block design. Effects were determined on plasma or serum concentrations of 25(OH)D, 24,25-dihydroxyvitamin D, calcitriol, parathyroid hormone, ionized calcium, urinary excretions of phosphorus, calcium and magnesium, and clinical hematology and chemistry panels. RESULTS: The lowest concentration of dietary 25(OH)Dsupported elevation of vitamin D status, with no adverse effects. Supplementation of 8.4 µg/kg 25(OH)Dhad significant effects on the urinary magnesium: creatinine ratio. Increasing supplementation up to 11.8 µg/kg 25(OH)Dhad significant effects on plasma concentrations of calcium and magnesium, and vitamin D metabolites. CONCLUSIONS AND RELEVANCE: Dietary supplementation with approximately 5.0 µg/kg of 25(OH)Dor the ingested equivalence of 0.09 µg of 25(OH)Dper metabolic body weight (kg) is a safe, potent and effective means for raising vitamin D status in cats. A higher dose with approximately 11.8 µg/kg of 25(OH)Dresulted in elevation in C-3 epimers of 25(OH)Dand slight elevation in plasma magnesium and calcium concentrations above their respective reference intervals.