Question

what is the relationship between calcium and cancer? vitamin D and cancer ?

please I need a long answer about 2 pages in details and citation .

Answer 1

Research has proved a link between high calcium intake and the risk of some types of cancers like prostrate cancer in men and breast cancer in women. Articles published in The American Journal of Clinical Nutrition, Vol 74, Issue 4 , 1st October 2001, pages 549 to 554 , by June M Chan and associates , has given a link between the two. High calcium intake, mainly from dairy products, lowers the concentration of 1,25- dihydroxyvitamin D3 , a hormone thought to protect against prostrate cancer. However , no concrete results could be established from the results of epidemiologic studies of this hypothesis.

Studies performed over 11 years of follow up on about 3000 men, led to documentation of roughly 1012 incident cases of prostrate cancer in those men who consumed more than 600 mg od calcium per day from dairy products, had a lower plasma 1,25- dihydroxyvitamin D3 as compared to those men who consumed less than 150 mg Ca/day.

Since prostrate cancer remains the most common cancer among men in the United States and is the leading cause of cancer deaths, these findings are of special interest among researchers. But , there is a lot of confusion over the link between Ca intake and occurance of prostrate cancer among men. The prospective Health Professionals Follow-up Study [ HPFS] reported a multivariate RR of metastatic prostrate cancer for men consuming more than 2000 mg Ca/day compared with those consuming less than 500 mg Ca/day. In an analysis limited to calcium from supplements only, the association remained strong, indicating that calcium enhanced risk. Studies performed on a large population based case control study in Sweden also found a link between dietary calcium and risk of metastatic prostrate cancer.

Mammographic breast density is strongly related to breast cancer. Some Harvard University studies have found that calcium and Vitamin D may help protect premenopausal women from developing breast cancer. It may also reduce the risk of breast cancer spreading to the bones.

Breast calcifications are small deposites of calcium in the breast tissues of women. They are quite common and are normally benign [ non cancerous ] . But in some instances, breast calcification might indicate early breast cancer.

Papers published by Yan Cui and Thomas E. Rohan in Cancer Epidemiology, Biomarkers and Prevention , reviewed the connection between Vitamin D , calcium and breast cancer.

Vitamin D and calcium are metabolically interrelated. Experimental studies have shown their anticarcinogenic effects because they help to regulate cell proliferation, differenciation and apoptosis in normal and malignant breast cells.

Contrary to this , several lines of evidence suggest that Vitamin D and calcium may be involved in development of breast cancer in women. but there are no concrete evidence for this]

Ecological studies have associated high levels of sunlight exposure to low incidence of breast cancer. Since our skin synthesizes Vitamin D in sunlight , it can be concluded that high levels of Vitamin D can reduce the risk of breast cancer among women.

Humans ingest vitamin from plant and animal food sources like fish, eggs, dairy products and vegetables. Vitamin D occurs in two forms- Vitamin D3 [ from animal sources] and Vitamin D 2 [ from plant sources] Recent studies in humans has indicated that Vitamin D3 is effective in increasing serum 25- hydroxyvitamin D , the precursor of biologically form of Vitamin D i.e 1,25 [ OH] D. An additional source of Vitamin D is sunlight exposure , which can convert 7- dehydrocholesterol into Vitamin D3 in the skin.

Circulating 1,25[OH]2D plays an important role in calcium homeostasis by participating in a feedback loop that maintains the level of calcium within its regulated range. It has been found that 1,25 [OH]2D modulates specific genes and can inhibit cell proliferation and differenciation. Both calcium and Vitamin work together to inhibit the proliferation of malignant cancer cells.

Hence we can safely conclude that calcium and Vitamin D have a role in suppressing breast cancer in women .

More research is required to establish a confirmed relationship between calcium, Vitamin D and cancer. Till date, all the studies point towards a suppresive effect of calcium and Vitamin D on breast cancer.

In the case of prostrate cancer, high levels of calcium intake has been related to a higher risk of prostrate cancer in men .