April 21, 2006
Several of the World’s leading vitamin researchers advocate a much higher vitamin D-intake. They believe that up to every third death from cancer may be prevented.
“I challenge anyone to find a field or a nutritional substance or any other factor with as effective cancer-fighting properties as vitamin D.”
So said Edward Giovanucci, professor at Harvard University, last year in a speech to the American Society for Cancer Research.
More and more agree with Giovanucci, amongst them, several professors from well-renowned universities. A few months ago Cedric Garland, an absolute pioneer in the field, stated that it has been proved that the risk of cancer can be lowered dramatically with vitamin D. These are big words. Garland is a professor at the University of California in San Diego.
Giovanucci has together with six others, of these, no less than three are professors from Harvard, confirmed the claim further. In a quite laborious study they have confirmed the close connection between a vitamin D deficiency and cancer.
Since World War II it has been known that especially cancer in the alimentary canal is seen relatively seldom in southern countries. Since sunlight is the most important source of vitamin D, it has earlier been guessed that it was vitamin D and not the sun, which offers protection. In numerous studies the incidence of cancer has been found to be highest where sunlight is weakest, and where the content of vitamin D in the blood is lowest. We are children of the sun. At the same time laboratory research in recent years has shown that this vitamin inhibits the growth of abnormal cells, counteracts the spread of cancer and prevents the formation of blood vessels in tumorous masses.
Giovanucci now finds further proof of the connection. Earlier in humans there has only been found an indirect connection between vitamin D and cancer. There has been a lack of data from whole groups of the population, that have had their blood content of vitamin D measured, and have then been followed for a number of years. But Giovanucci has found something to substitute this data.
Mega doses of Vitamin D
They took 1095 men from the big population study “Health Professionals Follow-Up Study”. These 1095 men had had their vitamin D-status measured (this means the content of vitamin D in the blood). In addition, a lot of things were known about their personal habits etc. Would it be possible to go backwards and calculate their vitamin D-status from their personal habits? Yes! An estimation of the approximate vitamin D blood content could be made, when the individual’s skin colour (eg. race), body mass, height, place of residence (southern/northern in the USA), the amount of physical activity, time of year and the content of vitamin D in the test subject’s diet and possibly supplements was known.
In this manner the group worked out a point-system for the direct calculation of vitamin D status. What especially contributed to a low status was a northern place of residence, dark skin colour, overweight and lack of exercise. The calculations proved correct for the 1095 test subjects. But would they be correct for other people? They were checked for another group of men with known vitamin D status. They were consistent!
Every single subject, of the 47,800 men in Health Professionals Follow-Up Study now had their vitamin D status calculated. In the course of approximately four years, about one in ten got cancer. About half that died from it.
To find the significance of vitamin D, they chose to compare dead men whose plasma values for vitamin D (25(OH)D3) deviated by 25 nmol/L (nanomol/liter). It was found that the risk of dying from cancer was no less than 29 percent lower in men with a high vitamin D status. Concerning cancer of the alimentary canal – it was 45 percent lower for men, who were otherwise identical with regards to age, weight and level of physical activity.
If these results are correct, every third death from cancer may be prevented in the course of a few years. Also in the UK. This is nothing but a sensation. But if one wishes to increase the plasma level of vitamin D by 25 nmol/L, one must receive a supplement of no less than 1,500 units of vitamin D during the winter. This is achieved if a supplement of four vitamin D tablets of 10 mcg (micrograms) is taken daily from August until April.
1,500 units will probably shock many. Is it not toxic? No, it is quite certain that there is no risk, even with a permanent supplement of 2,000 units daily. For comparison, the skin produces 20,000 units during half an hour in the sun in the summer.
Garland, who was mentioned above, recommends 1,000 units (25 micrograms) a day. Others say 2,000. Giovanucci and his colleagues from Harvard strongly recommend 1,500.
Under any circumstances: If you want the full advantage of vitamin D, it seems that the need is far greater than what we have gotten used to believe. Maybe it is close to what stone-age people received naturally from their diet.
By: Vitality Council
1. Giovanucci E et al. Prospective study of predictors of vitamin D status and cancer incidence and mortality in men. J Natl Cancer Inst 2006;98:451-9
2. Garland CF et al. The Role of Vitamin D in Cancer Prevention. Am J Public Health. 2006;96(2):9-18. 2005 Dec 27; [Epub ahead of print]