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High blood vitamin D levels reduce
risk of prostate cancer The 2005 Multidisciplinary Prostate
Cancer Symposium held in Orlando, Florida this month was the site
of a presentation by Haojie Li MD, PhD of Harvard University
School of Public Health of the finding that high plasma vitamin D
levels could help protect against the development of prostate
cancer and may also prevent the more aggressive form of the
disease. Using blood samples obtained in 1982 from 2400 healthy
participants in the Physician’s Health Study, Dr Li and
colleagues measured 25-hydroxyvitamin D (25 D) and 1,25
dihydroxyvitamin D (1,25 D), and ascertained variations in the
vitamin D receptor gene. Samples from 1,029 men who developed
prostate cancer over the 13 to 18 year follow-up period were age
and smoking-status matched with blood from 1,371 healthy men. The
Harvard and Brigham and Women’s Hospital researchers found that
men whose plasma levels of both forms of the vitamin were higher
than the median of the current study population experienced a 45
percent lower risk of developing aggressive prostate cancer than
those with lower levels. Presence of a genotype called homozygous
Fokl FF combined with high vitamin D levels lowered overall risk
by 55 percent, and the risk of developing aggressive disease by 77
percent. Dr Li, who was the study’s lead investigator,
concluded, "Our findings suggest that vitamin D plays an important
protective role against prostate cancer, especially clinically
aggressive disease. This research underscores the importance of
obtaining adequate vitamin D through skin exposure to sunlight or
through diet, including food and supplements."
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Further evidence of vitamin D's role against breast cancer 
09/08/2004
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Women with certain versions of the vitamin D receptor gene are almost
twice as likely to develop breast cancer than women with other versions of
the gene, finds a new study, that supports previous evidence of the
vitamin's protective effect against the disease.
But it demonstrates how the way in which the body utilises
the vitamin is also important.
Dr Kay Colston and colleagues at St George’s Hospital Medical School in London found that Caucasian women who have certain versions of the vitamin D receptor gene, which controls the action of vitamin D in the body, have a nearly two-fold greater risk of breast cancer than women with other versions of the gene.
They may also have a more aggressive form of the disease if it spreads, the researchers will report in the 15 August issue of Clinical Cancer Research (Vitamin D Receptor Gene Polymorphisms).
The findings support the idea that vitamin D plays a part in protecting the body against the disease and that different versions of the vitamin D receptor gene will affect this protective function.
Author Dr Michelle Guy said: “While it is known that 5 to 10 per cent of breast cancer cases are due to a genetic predisposition associated with well-characterised genes, like BRCA1, the underlying causes of the majority of all other breast cancers remain a mystery."
"We hope that by showing that natural variations in the vitamin D receptor gene can increase susceptibility to breast cancer, we are starting to unravel how breast cancer might develop in women who have no family history of the disease."
Scientists from St George's Hospital and the University of Birmingham reported earlier this year that breast tissue contains the enzyme that activates vitamin D, and levels of this enzyme are increased in breast tumours. Previously it was thought that the active form of vitamin D, calcitriol, which is a potent anti-cancer agent, was only made in the kidney.
In the new study, the researchers looked at the VDR gene of 398 women with breast cancer and 427 women without breast cancer. The women with breast cancer were significantly more likely to have a certain versions of the gene than the cancer-free women, they found.
The research is expected to offer progress in the future treatment for breast cancer, with risk assessment and drug regimes tailored to the individual patient.
It also adds to growing knowledge of the interaction of genes on the benefits of nutrients.
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Vitamin D may help lung cancer surgery |
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Vitamin D is a key factor in
helping patients benefit from surgery to treat early stage lung
cancer, says new research. The study, presented to the 96th Annual Meeting of the American Association for Cancer Research, showed that patients with high vitamin D intake – having had surgery in months with lots of sun - were more than twice as likely to be alive five years after surgery, compared to patients with low vitamin D intake who had wintertime operations. However, the researchers added they could not yet explain the link between vitamin D and surgery outcome and needed to validate the study, though a number of other studies have hinted that vitamin D may work to inhibit various cancers. “Animal studies have shown that treatment of cancer with vitamin D demonstrates both anti-proliferative and anti-invasive properties, but we don’t know if that is true in humans with cancer,” said the lead investigator, Dr. Wei Zhou. “So the best way we can make some sort of association is to look at differences in what happens after treatment of cancer between patients who use high levels of vitamin D through their diet and supplements, as well as through sunlight exposure, compared to patients who do not.” He cautioned that this research did not mean that patients should try and time their operations for a particular season, but if the results were validated, supplementation with vitamin D could be beneficial for survival. The research team looked at disease free survival (DFS) and overall survival (OS) in 456 patients who had early stage non-small cell lung cancer. A variety of different lung tumor types were included in the mix of patients, of whom 40 percent were current smokers. Only 9 percent of patients received radiation treatment following surgery, and 1 percent received chemotherapy. When the joint effects of surgery season and vitamin D intake were considered, the researchers found that patients with the highest vitamin D intake who had surgery in the summer had statistically significantly better outcomes - a three-fold better disease-free survival and a four-fold better overall survival - than patients who had surgery during winter with the lowest vitamin D intake. The five-year disease-free survival was 83 percent versus 46 percent, respectively, and the five-year overall survival rate was 72 percent compared to 30 percent, respectively.
Vitamin D levels low in almost all hip fracture patients
Nearly all hip fracture patients are deficient, sometimes severely, in vitamin
D, researchers in Scotland reported this week. In around a quarter of the group studied, levels were so low that they were "effectively unrecordable", said the authors in the online issue of Current Medical Research and Opinion (DOI: 10.1185/030079905X59148). Vitamin D currently only makes up 4 per cent of all vitamin sales and lags well behind calcium in terms of bone health supplements. But increasing evidence underlines its importance in protecting against fractures. In a second prospective study phase, the researchers looked at vitamin D levels among the first 50 patients admitted to the hospital with an osteoporosis fracture after November 2004. More than 80 per cent had vitamin D levels below 70 nmol/L and 72 per cent had vitamin D levels below 50 nmol/L. "Although numbers were too small to justify extensive subgroup analyses, the mean vitamin D level in the 13 patients with hip fracture was lower than in the 37 with non-hip fractures," said the researchers. They conclude: "It may be that vitamin D represents a correctable risk factor for fragility fracture in the elderly, possibly specifically for the hip."
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