Vitamin D bread raises bone mineral density in elderly
A bread fortified with very high levels of vitamin D appeared to be much better at protecting bone health in elderly people than bone-building drugs, according to a study presented this week. Speaking at the Experimental Biology meeting in San Diego, the researchers said that elderly patients who consumed 5000 IU of vitamin D and 320 mg calcium carbonate a day through a specially formulated bread had a 28 per cent increase in lumbar bone mineral density after one year. This compares to the 8 per cent increase in bone mass density typically achieved with bone-building drugs. “We designed the study two years ago and could not get approval for use of this much vitamin D,” he said. The European Union’s Scientific Committee on Food recommends an upper safe level of 50mcg (2,000 IU) vitamin D, the same level recommended by the US Food and Nutrition Board. It is thought that higher doses of vitamin D can increase calcium levels circulating in the blood, causing the potentially serious condition, hypercalcaemia. The new study, carried out by Dr Veronica Mocanu and colleagues at the University of Medicine in Isai, Romania, and Dr Reinhold Veith at the University of Toronto, tested for calcium excretion and found that it did not rise above ‘normal values’. The findings will add fuel to the debate raging over the role of vitamin D in health. Vitamin D is naturally produced by the skin’s exposure to UV rays in sunlight. Studies increasingly link higher risk of certain health conditions in countries with little sunshine for long periods of the year to a vitamin D deficiency. The bread was tested on 45 elderly nursing home patients in Romania, a location chosen because it is at a northern latitude similar to many cities where solar ultraviolet radiation intensity is low, especially in winter months. Previous research has found that vitamin D supplementation reduces the risk of potentially life-threatening falls among institutionalised elderly people by more than 20 per cent.
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 Physicianâ€™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 Womenâ€™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 studyâ€™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.”
Further evidence of vitamin D’s role against breast cancer
09/08/2004 – 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.
Vitamin D may help lung cancer surgery
Vitamin D is a key factor in helping patients benefit from surgery to treat early stage lung cancer, says new research.
Researchers at Harvard School of Public Health and Harvard Medical School said that successful surgery appeared to depend on the level of vitamin D present in a patient – a calculation that includes food sources, supplements, as well as the season of the year during which the operation is performed.
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.
Reviewing the cases of 548 patients over the age of 60 who were admitted at South Glasgow University Hospital during a four-year period, the researchers found that 97.8 per cent had vitamin D levels below normal.
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.”