Mineral metabolism in growing cats: changes in the values of blood parameters with age

Abstract

The purpose of this study was to describe changes in calcium, phosphorus, magnesium, parathyroid hormone, calcitriol and calcidiol in cats from 3 to 15 months of age. Fourteen European shorthair healthy cats of both sexes (seven males, seven females) belonging to a research colony were studied from 3 to 15 months of age. Plasma concentrations of total calcium, ionised calcium, albumin, phosphorus, magnesium, intact parathyroid hormone (I-PTH), whole parathyroid hormone (W-PTH), calcidiol and calcitriol were measured at 3, 6, 9, 12 and 15 months of age. From 3 months of age to adulthood cats showed a decrease in calcium (both total and ionised), phosphorus and magnesium. No major changes in PTH were evident, although the ratio of W-PTH:I-PTH decreased significantly with age. A reciprocal change in vitamin D metabolites (decrease in calcitriol and increase in calcidiol) was identified during the growing process. Our results, showing changes in most parameters of mineral metabolism during growth, reinforce the need to use adequate age-related reference values for diagnostic purposes.

Vitamin D status in cats with feline immunodeficiency virus

“…Currently, knowledge regarding the effects of age on vitamin D status in cats is limited to studies indicating that 25(OH)D increase over time in growing cats (Pineda et al . ).…”

“…Lastly, both very old and very young cats were enrolled in the study and age may vary being these groups. Currently, knowledge regarding the effects of age on vitamin D status in cats is limited to studies indicating that 25(OH)D increase over time in growing cats (Pineda et al 2013).…”

Effects of two calculolytic diets on parameters of feline mineral metabolism

“…However, as the concentrations of calcitriol measured after feeding the calculolytic diets were within the reference limits (Pineda et al . ) and did not affect plasma calcium concentrations, the significance of the reduced calcitriol is questionable. The requirements for vitamin D in adult cats have not been well studied and the vitamin D requirement for kittens has been and is used as the basis for the adult recommendation, 6.25 µg/kg of diet (NRC ).…”

“…The lower vitamin D content of the calculolytic diets (when compared with the maintenance diet) is likely to have resulted in a decrease in the plasma concentration of calcitriol, the major vitamin D metabolite. However, as the concentrations of calcitriol measured after feeding the calculolytic diets were within the reference limits (Pineda et al 2013) and did not affect plasma calcium concentrations, the significance of the reduced calcitriol is questionable. The requirements for vitamin D in adult cats have not been well studied and the vitamin D requirement for kittens has been and is used as the basis for the adult recommendation, 6·25 µg/kg of diet (NRC 2006).…”

“…Plasma concentrations of calcitriol were measured using a radioimmunoassay (Immunodiagnostic Systems Ltd, UK) that has been validated for cats (Pineda et al 2013). PTH was measured using an immunoradiometric assay (Scantibodies Laboratory Inc., USA) designed for the quantitative determination of human "intact" PTH validated for measurement of feline PTH (Pineda et al 2012).…”