Vitamines et minéraux

Calcium is an essential nutrient of the human body. The main source of calcium in the body is from the food we eat. But the absorption of calcium is limited due to the presence of phytates, oxalates, etc. Many countries in Asia have average dietary calcium intake less than 500 mg/day. Countries in Africa and South America mostly have low calcium intake between about 400 mg/day and 700 mg/day. Only Northern European countries have national calcium intake greater than 1000 mg/day. Hence there is a need to depend on calcium supplements. Several forms of calcium compounds are used as supplements. Calcium supplementation has its own advantages and disadvantages. The inability to ascertain proper absorption from the gut, selection of suitable compound as per clinical condition, dose fixation etc. are challenges of modern calcium supplementation. Ayurveda uses drugs from plant, animal and mineral origin as calcium supplements. Ayurvedic calcium supplements are used in a wide range of morbidities ranging from fever to cardiac ailments. These articles highlight the calcium supplementation from ayurvedic perspective in the light of the classical literature and recent researches in these aspects.

Most evidence studies have concluded that there is an inverse association between blood levels of calcidiol and cancer incidence and survival. These findings especially apply in colorectal and breast cancer (BC). The phenomenon of the multidirectional activity of vitamin D is possibly due to the presence of the vitamin D receptor (VDR) in most non-skeletal human cells including cancer cells. The crucial is that a wide range of the genes regulated by VDR are related with cell proliferation, differentiation, angiogenesis and metastasis. The aim of this paper was to present recent data on the possible role of vitamin D as an chemopreventive or therapeutic agent against BC through considering the anticancer mechanisms induced by this vitamin as well as presenting the results of clinical studies on the impact of vitamin D status on BC incidence, survival and response to therapy. This review is based on an electronic search of articles in the PubMed database, including papers published mostly within last five years in that field and selected according to the following criteria: well commented studies concerning the association between vitamin D status and BC risk, response to therapy or survival, with the vitamin D supplementation outline and statistical data.