Sunshine supplement: The study found that people who took the vitamin had about a seven per cent reduction in their chance of an early death.
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SYDNEY: A healthy dose of vitamin D has the ability to prolong your life, say experts behind the widest yet analysis of the supplement's effects.
The study, detailed this week in the U.S. journal Archives of Internal Medicine, found that vitamin D supplements significantly decrease rates of mortality, but researchers, as yet, don’t understand why.
Deficiency of the 'sunshine' vitamin – so-named because we produce it from another molecule in our skin when exposed to the Sun's rays – has long been considered a risk factor for bone diseases such as rickets and osteoporosis, as well as cancer and heart disease. The nutrient can also be obtained from eating foods such as salmon and tuna, eggs, and dairy products.
Staving off fatal conditions
To find our more about the suspected life-boosting benefits of vitamin D, epidemiologist Philippe Autier of the International Agency for Research on Cancer in Lyon, France, and Sara Gandini of the European Institute of Oncology in Milan, Italy, collected vast amounts of data from 18 existing trials of the supplement. These trials included data on nearly 60,000 mostly middle-aged and elderly adults from several countries.
Their results showed that people who took the supplement had about a seven per cent reduction in their chance of an early death over people who didn’t take it. The analysis, however, didn’t pinpoint what was responsible for the effect.
Autier and Gandini argue that the vitamin's effects on metabolism and the immune system may play a key role in staving off fatal conditions; but further research is needed to confirm this. Additionally, they argue, vitamin D’s effects on the growth of cells might “reduce aggressiveness” of cancers, and its role in boosting cholesterol-reducing statins may protect against heart disease.
“The paper is very important because it pools data that had been around, but mostly poor quality,” commented nutritionist Samir Samman of the University of Sydney in Australia. "The authors have combined the results of 18 studies that address the idea that vitamin D supplements could decrease mortality rates in older people. The answer is yes, it does."
“The results are remarkable,” said Edward Giovannucci of Harvard School of Public Health in Boston, U.S., in an accompanying editorial in the same journal. Giovannucci calls for a more “proactive attitude” from health workers in identifying people with vitamin D deficiency.
Antioxidant rethink
In related news, researchers at John Hopkins University in Baltimore, Maryland, have discovered a new mechanism by which antioxidants, such as the vitamins C and E, fight cancer.
Scientists previous thought that cancer-causing free radicals did their damage simply by reacting with DNA, causing it to mutate. However the new study of mice, published in the U.S. journal Cancer Cell, suggests that free radicals might also work by stabilising a developing tumour and encouraging its growth.
The authors propose that by mopping up free radicals antioxidants might therefore have more of an effect on destabilising tumour growth than preventing cancer-causing DNA damage.
