Animals in captivity should receive adequate sunlight exposure for sufficient generation of vitamin D [25(OH)D]. In the present study, 25(OH)D serum levels of 84 Callithrix penicillata primates were evaluated. To determine 25(OH)D levels of those animals; to evaluate the influence of gender and period of sunlight exposure on their 25(OH)D levels. Three groups were evaluated: group 1 (n = 29) on free sunlight exposure; group 2 (n = 34) on partial sunlight exposure; group 3 (n = 21) without sunlight exposure. The obtained 25(OH)D values were: group 1, 121.2 +/- 33.3 ng/ml; group 2, 115.2 +/- 32.2 ng/ml; group 3, 53.3 +/- 10.4 ng/ml. Significant statistical differences were obtained between groups 1 and 3 (p < 0.001) and groups 2 and 3 (p < 0.001); no statistical difference was found between genders. Direct sunlight exposure is essential for 25(OH)D sufficiency and it is proposed that the 25(OH)D normal range for captive Callithrix penicillata would be from 104.8 to 137.1 ng/ml (CI = 95%).