Estimation of vitamin D₃ and 25-hydroxyvitamin D₃ in muscle and adipose tissue of rats and man

Abstract

An assay is described based on a high pressure liquid chromatography system for measurement of vitamin D₃ and 25-hydroxyvitamin D₃ concentration in adipose tissue and muscle. The sensitivity of the assay is < 1 ng/g of tissue. Neither vitamin D₃ nor 25-hydroxyvitamin D₃ were found in tissues of vitamin D-deficient rats using this method. 25-Hydroxyvitamin D₃ could not be-detected in adipose tissue and very little was found in muscle of normal rats. The mean vitamin D₃ concentrations in 15 samples of human perirenal adipose tissue was 45.3 ng/g ± 22.2 (SD) and in 6 samples of axillary tissue 115.6 ng/g ± 52.4 (SD). Human adipose tissue contains a substantial amount of vitamin D₃ and its contribution to the maintenance of vitamin D status is discussed.