This study was designed to investigate the protective role of protein (Pr) and calcium (Ca) on effects of fluoride (F) induced in nonspecific immunological function in New Zealand rabbits fed a Pr and a Ca nutritionally deficient (malnutrition) diet. Eighty healthy 30-day-old rabbits (1.07±0.25 kg) were divided randomly into four equal groups of twenty (female:male = 1:1). The four groups were maintained on distilled water and fed for 120 days: (1) a malnutrition control (MC) diet (8.58% Pr, 0.49% Ca = MC group); (2) the MC diet plus HiF (442 mg NaF (=200 mg F ion]/kg diet = HiF group); (3) a Ca deficient diet plus HiPr+HiF (18.41% Pr, 0.46% Ca, plus HiF diet = HiPr group); and (4) a Pr deficient diet plus HiCa+HiF (8.35% Pr, 2.23% Ca, plus HiF diet = HiCa group). Growth of the rabbits was markedly inhibited by HiF ingestion. Pr supplementation significantly alleviated the HiF-induced decrease in rate of growth. Compared to the MC group, the serum total Pr (TPr) and serum albumin (ALB) content in the HiF group were significantly decreased on average by 12.4% and 7.7%, respectively. Pr or Ca supplementation markedly increased serum TPr and ALB content compared to the HiF group. Compared to the MC group, tissue acid
phosphatase (ACPase), serum lysozyme (Lys), and serum ACPase concentrations were significantly increased with HiF ingestion but were significantly alleviated by Pr and Ca supplementation. These findings indicate that HiF ingestion seriously damages nonspecific immune function in rabbits and that Pr and Ca can play protective roles against F-induced damage to immune functions.