Digestive Efficiency Mediated by Serum Calcium Predicts Bone Mineral Density in the Common Marmoset (Callithrix jacchus)

Abstract

Two health problems have plagued captive common marmoset (Callithrix jacchus) colonies for nearly as long as those colonies have existed: marmoset wasting syndrome and metabolic bone disease. While marmoset wasting syndrome is explicitly linked to nutrient malabsorption, we propose metabolic bone disease is also linked to nutrient malabsorption, although indirectly. If animals experience negative nutrient balance chronically, critical nutrients may be taken from mineral stores like the skeleton, thus leaving those stores depleted. We indirectly tested this prediction through an initial investigation of digestive efficiency, as measured by apparent energy digestibility, and serum parameters known to play a part in metabolic bone mineral density of captive common marmoset monkeys. In our initial study on 12 clinically healthy animals, we found a wide range of digestive efficiencies, and subjects with lower digestive efficiency had lower serum vitamin D despite having higher food intakes. A second experiment on 23 subjects including several with suspected bone disease was undertaken to measure digestive and serum parameters, with the addition of a measure of bone mineral density by dual-energy x-ray absorptiometry (DEXA). Bone mineral density was positively associated with apparent digestibility of energy, vitamin D, and serum calcium. Further, digestive efficiency was found to predict bone mineral density when mediated by serum calcium. These data indicate that a poor ability to digest and absorb nutrients leads to calcium and vitamin D insufficiency. Vitamin D absorption may be particularly critical for indoor-housed animals, as opposed to animals in a more natural setting, because vitamin D that would otherwise be synthesized via exposure to sunlight must be absorbed from their diet. If malabsorption persists, metabolic bone disease is a possible consequence in common marmosets. These findings support our hypothesis that both wasting syndrome and metabolic bone disease in captive common marmosets are consequences of inefficient nutrient absorption.

25‐OH‐vitamin D, parathyroid hormone, and calcium serum levels in captive common marmosets (Callithrix jacchus): Reference values and effect of age, sex, season, and closure of long bone epiphyses

“…Mainly vitamin D levels, and to a lesser extent also PTH and calcium levels, have already been published by other authors, but these measurements were performed in small subsets of animals (7-25 measurements in Callithrix jacchus and 15-34 measurements in Callithrix penicillata) (see Table S2). 5,6,[10][11][12][13] When comparing our values with these data, the large variation in 25-OH-vitamin D serum concentrations in all studies is noteworthy: Mean serum levels ranged from 154 ± 51.92 nmol/L (measured in free-ranging C. penicillata, a closely related species) to 1183.10 ± 239.62 nmol/L (in C. jacchus). In our study, a mean 25-OH-vitamin D level of 207.08 ± 103.5 nmol/L was found which is situated at the low end of this spectrum.…”

Serum Albumin and Body Weight as Biomarkers for the Antemortem Identification of Bone and Gastrointestinal Disease in the Common Marmoset

“…Such a link between bone and GI disease supports the pathogenesis recently proposed by Jarcho et al ., where GI inflammation leads to malabsorption of critical nutrients, including those important for bone homeostasis [29]. This then could lead to weight loss and muscle wasting typical of MWS and decreased bone density characteristic of MBD.…”

Identification of possible nutritional and stress risk factors in the development of marmoset wasting syndrome

“…Fiber may be a little‐studied link leading to the development of MWS (Jarcho et al, ). In this study, we determined that fiber may have a protective effect against MWS.…”