Vitamin D in camel

Camel meat and milk contains minerals, proteins, good cholesterol and vitamins. In Human, vitamin D is of great importance for health and recommendations for its intake have recently been increased considerably. In domestic ruminants, circulating vitamin D levels may be influenced by several factors such as photoperiod, nutrition, physiological stage, ambient temperature, attitude and season, whereas, in meat, vitamin D content may be impacted by vitamin D status of animal, ageing and cooking. Thus, highlighting physiological role of this hormone justifies its growing interest. However, the information available on nutritional value of camel milk and meat is very limited, and in the litterature, there are very few reports evaluating the vitamin D levels and their variations in blood and these products in the dromedary camel. In this context, this review proposes a synthesis of current knowledge about the vitamin D in the dromedary camel and discusses findings considering those obtained in other mammal animals. In the camel, 25-hydroxyvitamin D3 (25-OH-D3) amounts in serum (ng/mL), liver, kidney and muscle (ng/g) were 390±45; 7.071±1.003; 6.154±1.067 and 4.241±1.045 respectively. Values in liver were significantly higher (P<0.05) than those of muscle. Serum 25-OH-D3 levels in camels were 10 to 15 times very higher than those of ruminant species. The circulating levels of 25-OH-D and 1,25-dihydroxyvitamine D were very high in lactating camels and their newborns, suggesting a good intestinal absorption, mammary excretion and bone fixation of calcium (Ca) and phosphorus (Pi). In fact, these metabolites increased the levels of Ca and Pi in the blood of newborn camel and the milk of lactating camels. The circulating levels of 25-OH-D were significantly (P<0.05) lower during winter than those observed during summer, while, tissue levels of 25-OH-D3 showed no seasonal variation. The camel meat is a good source of 25-OH-D and during a cold storage at 4°C of 10 days, raw and cooked meat levels of 25-OH-D showed no significant variation. Furthermore, these levels were positively correlated with pH and negatively correlated with redness of juice, drip loss and malondialdehyde contents. To conclude, in the dromedary camel, 25-OH-D may be implicated in bone metabolism during lactation and postnatal growth, quality characteristics of meat, antioxidant status of blood and meat and other functions like immunity and reproduction.