I saw a news article recently about vitamin D being an anti-cancer vitamin. Is there much truth in this idea, or is it just wishful thinking?
If vitamin D really is an anti-cancer vitamin, what is the best dosage to use?
Yes, Vitamin D really is a cancer-prevention vitamin, and it appears to be a very good one. Vitamin D is also an excellent bone-strength enhancer.
Let us look at the evidence for both of these claims.
Vitamin D as a cancer preventative
This vitamin came to the attention of cancer researchers in the 1950s but little was done to explore its potential in therapy
or prevention. In the 1980s it was noted that colon cancer rates are lower when vitamin D consumption is higher. But again, the gears of medicine ground along so slowly that another ten years passed before the medical world began to take
the association seriously.
More recently there has been a rapidly growing interest in the use of vitamin D as a cancer treatment and preventative. Research during the past decade has shown that vitamin D can inhibit the proliferation of a wide variety of cell types. According to one reviewer, this “antiproliferative action makes [vitamin D] a possible therapeutic tool to treat … different
types of cancer.” For example, a 2006 review of vitamin D treatment of prostate cancer reported that the vitamin “showed significant antineoplastic
activity in pre-clinical models of prostate cancer and many other tumor types.” A recent compilation of statistics from clinical trials revealed that “an impaired vitamin D status is associated with a
20-30% increased breast cancer incidence and 10-20% increased mortality.” The clinical data that supports these conclusions was collected from studies that used relatively low doses of vitamin D
— typically less than 1000 i.u. per day.
In 2000, researchers at Creighton University began a four-year clinical trial to test the anti-cancer and anti-osteoporosis
effects of a vitamin D supplement combined with calcium. Some of the subjects received the active supplement (1100 i.u./day
of vitamin D3 plus 1400-1500 mg/day of calcium), and others received a placebo. This long-overdue experiment, ‘the Creighton
Study’, showed startling results: a 77% reduction in overall cancer risk.
Vitamin D as a bone strengthener
Vitamin D’s history of use as a bone strengthener goes back at least to the 1920s, although people have used it unwittingly
since ancient times, inasmuch as they learned to avoid getting vitamin D deficiency diseases by eating certain foods or by
spending time in the sun — fish, eggs, butter, and beef are dietary sources of this vitamin, and sunlight stimulates its production
in the skin. There are many vitamin D deficiency diseases, the most famous of which are rickets and osteoporosis.
The Creighton Study showed that for those subjects who received the active supplement (1100 i.u./day of vitamin D3, combined
with 1400-1500 mg/day of calcium), their Bone Mineral Density rose — whereas for those who received the placebo, their BMD
fell.
Supplement industry responds quickly to discoveries
Unlike the medical world, the supplement world responds quickly to research successes. Within a few months of the announcement
of the Creighton Study’s results, higher-dosage vitamin D3 products appeared on the supplement market. Among these were two
new products from LifeLink: Formula CS Plus and D3ZO.
- Formula CS Plus replicates the formula used in the Creighton Study, but with added ingredients to increase its effectiveness for preventing
cancer and increasing bone strength.
- D3ZO is a very high potency vitamin D3 supplement that relies purely on D3 and Zinc Orotate for its anti-cancer and bone-strengthening
effects.
In contrast to the supplement industry’s rapid response to the discoveries about vitamin D3, the medical establishment remains
in its typical foot-dragging mode. For example, the NIH (U.S. National Institutes of Health) admits that experts are now advocating
vitamin D dosages in the thousands of i.u./day, yet the NIH itself continues to advocate vitamin D consumption at only 200-600
i.u./day, and falsely suggests to readers that doses higher than 2000 i.u./day may be toxic.
Vitamin D3
The optimum amount of vitamin D3 consumption undoubtedly differs from person to person, and certainly depends also on what condition
one hopes to alter — for example, the best dosage for cancer prevention may not be the same as that for bone strength. In
any case, the optimum amount is not really known for any condition. We do know, from the Creighton Study, that 1100 i.u. per day is better than 400 i.u., and that experts are leaning toward considerably
higher doses than 1100 i.u. One prominent researcher suggests 10,000 i.u./day. Some supplement companies are offering vitamin D3 products containing as much as 50,000 i.u. per capsule. LifeLink settled
on 4000 i.u. for Formula CS Plus in order to enhance the formula without going too far beyond the parameters shown to be effective
in the Creighton Study. And 25,000 i.u. per capsule was chosen for the high-potency D3ZO product because this is half the
dosage for which safety data have been collected.
Good overviews of vitamin D can be found at Wikipedia and at the University of California at Riverside — however, the dosages suggested in these reviews are obsolete.
Side effects of vitamin D supplementation
No serious side effects were observed during the Creighton Study. Theoretically, an excess of vitamin D could lead to ‘hypercalcemia’ — too much calcium in the blood, causing one to feel
lethargic. In that case, the supplement would be working too well at making calcium bioavailable and one should try reducing the dose.
— Dr. Alexis Zarkov, Ph.D.
You can contact Dr. Zarkov at AskDrZarkov@yahoo.com.
Last modified 2008.Apr.30
References
[1]
Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial.
Am J Clin Nutr. 2007 Jun; 85(6):1586-91
Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP
[2]
Calcium and Vitamin D Supplementation Improves Bone Health in a Population-based Sample of Postmenopausal Women
American Society for Bone and Mineral Research, 29th Annual Meeting: Poster T359; [Not available online]
J. Lappe, K. Davies, D. Travers-Gustafson, G. Haynatzki, R. Heaney, R. Recker
[3]
Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety.
Am J Clin Nutr. 1999 May; 69(5):842-56
Vieth R
[4]
Vitamin D signalling pathways in cancer: potential for anticancer therapeutics.
Nat Rev Cancer. 2007 Sep; 7(9):684-700
Deeb KK, Trump DL, Johnson CS
[5]
Antiproliferative role of vitamin D and its analogs--a brief overview.
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[6]
Vitamin D and cancer.
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[7]
[Vitamin D and breast cancer]
Ugeskr Laeger. 2007 Apr 2; 169(14):1299-302
Nielsen LR, Mosekilde L
[8]
Vitamin D supplementation and total mortality: a meta-analysis of randomized controlled trials.
Arch Intern Med. 2007 Sep 10; 167(16):1730-7
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[9]
An estimate of cancer mortality rate reductions in Europe and the US with 1,000 IU of oral vitamin D per day.
Recent Results Cancer Res. 2007; 174:225-34
Grant WB, Garland CF, Gorham ED
[10]
Calcitriol in the treatment of prostate cancer.
Anticancer Res. 2006 Jul-Aug; 26(4A):2647-51
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[11]
Vitamin D
Wikipedia website
[12]
About Vitamin D
University of California, Riverside; Vitamin D Home Page
Center for Visual Computing
[13]
Do sunlight and vitamin D reduce the likelihood of colon cancer?
Int J Epidemiol. 1980 Sep; 9(3):227-31
Garland CF, Garland FC
[14]
Dietary Supplement Fact Sheet: Vitamin D
website of Office of Dietary Supplements, National Institutes of Health, 2008.April.18
Disclaimer: The information provided in this “Ask Dr. Zarkov” article contains no medical advice whatsoever — it contains
biological information. Nothing in the article constitutes an effort to persuade readers to use, or not to use, this biological information as a
basis for action.
2008