| Abstrakt: |
Rickets and osteomalacia have been reported frequently in captive callitrichids. Some have assumed that these conditions are a consequence of unmet, unusually high requirements for vitamin D and that these high requirements are characteristic of all New World primates. As a consequence, certain commercial diets formulated for New World primates contain such high concentrations of vitamin D that their consumption by other species has resulted in signs of vitamin D toxicity. This study was conducted to assess the vitamin D status of captive cotton-top tamarins consuming diets providing either 2,500 or 26,000 IU of vitamin D3/kg dry matter. These diets had been consumed for at least 2 years before the study, with the lower vitamin D intakes by six tamarins (0.5 to 9 years old) in a zoo colony and the higher vitamin D intakes by 24 tamarins (2 to 12 years old) in a pharmaceutical research laboratory. Although not measured in this study, none of the dietary ingredients has been shown to contain vitamin D2. Serum 25-hydroxyvitamin D (25(OH)D) concentrations in the captive tamarins were compared with serum 25(OH)D concentrations (range, 25.5120 ng/mL; 64300 nmol/L) reported by others in healthy wild tamarins in Colombia, South America. Concentrations of 25(OH)D in serum from zoo tamarins consuming 2,500 IU vitamin D3/kg dietary dry matter ranged from 48 to 236 ng/mL (120590 nmol/L), whereas those in serum from laboratory tamarins fed 26,000 IU vitamin D3/kg dietary dry matter ranged from 11 to 560 ng/mL (281,400 nmol/L), with no significant (P > 0.05) association between serum 25(OH)D concentration and sex or age. However, in the laboratory tamarins, serum 25(OH)D concentrations ranged from 46 to 60 ng/mL (115150 nmol/L) in one 8-year-old male and four 12-year-old females that had four to nine pregnancies each. Younger females (25 years old) that had zero or one pregnancy and the other males (312 years old) generally had serum 25(OH)D concentrations above 126 ng/mL (315 nmol/L). None of the individuals in the zoo colony showed signs of colitis. Of the two tamarins in the laboratory group with 25(OH)D levels below 50 ng/mL (125 nmol/L), one was a 4-year-old male with anorexia and cachexia associated with severe colitis. The second was a 7-year-old clinically normal, multiparous (five) female with normal hematology and clinical chemistry but histologic evidence of severe colitis. Because all other individuals in this group had histologic evidence of moderate to severe colitis but were normal in other respects, an unequivocal association between low serum 25(OH)D concentrations and colitis was not apparent. A dietary vitamin D3 concentration of 2,500 IU/kg dry matter was more than sufficient to support serum 25(OH)D concentrations equivalent to those found in the wild and, although the number of observations was small, supported apparently normal growth and adult weights, reproduction through five parities, and general health in a zoo colony showing no evidence of colitis. Zoo Biol 18:473480, 1999. © 1999 Wiley-Liss, Inc. |
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