The mainstream media has paid an unusual amount of attention to vitamin D in recent months. Earlier this year there were two back-to-back clinical studies establishing a strong link between higher levels of this vitamin, long-believed by most to be a pillar of bone health but little else, and the prevention of breast cancer. These studies literally made front page news in the prestigious Canadian national newspaper, the Globe and Mail.
Additionally, a more recent study among children went as far as to suggest that the existing Recommended Daily Allowance (RDA) for vitamin D be increased by 10-fold. Vitamin D has also been inversely linked to incidences of prostate cancer among men, and a very recent study among this gender has now revealed vitamin D may also help prevent the incidences of heart attacks as well.
The latter study was conducted by Harvard University’s School of Public Health. It involved the analysis of the medical history of 454 men aged 40-75 with a history of myocardial infarctions - including fatal ones - as the aforementioned records also encompassed those belonging to subjects who were deceased. These records were then examined against 900 healthy ‘control’ male subjects of the same age group, and after factors such as lifestyle (smoking, alcohol consumption, etc.) and diet were taken into account, the Harvard researchers made a significant observation regarding vitamin D. They found that men with lower circulating levels of the vitamin were 109% more likely to suffer a heart attack than those whose circulating levels of vitamin D were sufficient.
For the purposes of this study, vitamin D insufficiency was defined as 15 nanograms per millilitre (ng/mL)-or lower- of the vitamin in its active hormone form of 1,25 [OH]2D, while sufficiency was defined as at least 30 ng/mL. The latter number has been shown in very recent studies to require a daily intake of vitamin D (through diet or supplements) of at least 2,000 International Units (IU). The current RDA for vitamin D is 200 IU for children and adults up to the age of 50. The revision of the RDA for vitamin D to 800-1000 IU seems all but inevitable to many in both scientific and public circles, fuelled by mounting studies leading to ever-increasing calls to do so – calls that some have begun to describe as ‘deafening.’
Source: Giovannucci E, Liu Y, Hollis BW, Rimm EB. 25-hydroxyvitamin D and risk of myocardial infarction in men: a prospective study. Arch Intern Med. 2008 Jun 9;168(11):1174-80.
For more information see D3-5000 or Vitamin D3
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