peterants

An article in our local paper today refers to five different studies on Vitamin D. The first showed a significant association between low levels of Vitamin D in Alzheimer’s patients and poor performance on cognitive tests. The study was done after families of Alzheimer’s patients reported how well the patients did after starting Vitamin D supplementation.

The second study concluded that 1,000 to 2,000 IU of Vitamin D per day could reduce the incidence of colon cancer by 50%. The third study, by the same researchers also concluded that 2,000 IU of Vitamin D could reduce the incidence of breast cancer by 50%. The authors of that study also concluded that

…Vitamin D has the potential to reduce at least half of serious invasive cancers and make the remaining ones milder and far more treatable.

The fourth study found that, out of seven million white males in the US military, those with the highest levels of Vitamin D in their blood were 62% less likely to develop multiple sclerosis than those with low levels.

The fifth study related low levels of Vitamin D to flu susceptibility. The author of that study was quoted as saying that

Maybe the shot people need to get in the fall is not a flu shot, but a Vitamin D shot.

Then there was an article in the Life Extension Foundation update e-mail I receive:

A report published in the February, 2007 issue of the Journal of the American Geriatrics Society concluded that supplementing with vitamin D can help prevent nursing home falls in older men and women. Falls occur in approximately half of the residents of nursing homes each year, and render the patients more susceptible to further injury.

Kerry Broe and Douglas Kiel of the Institute for Aging Research at Hebrew Senior Life in Boston and colleagues at Boston Medical Center and Harvard analyzed data from a randomized, controlled clinical trial of 124 nursing home residents with an average age of 89. Participants received 200, 400, 600, or 800 international units (IU) vitamin D per day or placebo for five months.

At the study’s conclusion, 44 percent of the patients in the placebo group had fallen, compared with 20 percent of the group that received 800 IU vitamin D. The adjusted-incidence rate ratio of falls of the subjects in this group was 72 percent lower than that of the placebo group. Lower doses of vitamin D than 800 IU were not associated with any significant effects compared to placebo.

Over half of the subjects who were using a multivitamin supplement at the beginning of the study had suboptimal serum vitamin D levels of less than 20 nanograms per milliliter. When total vitamin D supplement intake was calculated to include multinutrient supplements, the group whose intake was in the lowest one-fifth of the participants had the greatest number of fallers, while the top fifth had the least.

And now two additional reasons to take Vitamin D supplements from the May 2007 issue of Life Extension Magazine. First, it shows promise in reducing the incidence of Type II diabetes:

Exciting research also indicates a possible therapeutic role for vitamin D in preventing diabetes.

Vitamin D supplementation may reduce susceptibility to type II diabetes by slowing the loss of insulin sensitivity in people who show early signs of the disease. Researchers studied 314 adults without diabetes and gave them either 700 IU of vitamin D and 500 mg of calcium daily or a placebo for three years. Among subjects who had impaired (slightly elevated) fasting glucose levels at the study’s onset, those taking the active supplement had a smaller rise in glucose levels over three years than did the controls, as well as a smaller increase in insulin resistance. The researchers concluded that for older adults with impaired glucose levels, supplementing with vitamin D and calcium may help avert metabolic syndrome and type II diabetes.

And it shows promise in the treatment and prevention of prostate cancer:

Aware that low vitamin D levels are a major risk factor for prostate cancer, researchers examined the vitamin’s preventive effect in a cancer-prone mutant strain of mice. Mutant and control mice were given vitamin D for four months either before or after developing the first signs of cancer. Vitamin D substantially reduced the occurrence of early cancerous changes in tissue, yet appeared to have no effect on the androgen (male hormone) system. This is crucial, because many conventional prostate cancer drugs impair androgen function. Human prostate cancer cells in culture show similar reductions in cancerous changes and proliferation when treated with vitamin D3 and a synthetic retinoid (a vitamin A-like compound)

A 1998 study demonstrated that vitamin D can reduce prostate cancer growth in human subjects. Seven men with recurrent prostate cancer following surgery or radiation (as measured by increasing levels of prostate-specific antigen, or PSA) were given a prescription form of vitamin D called calcitriol (Rocaltrol®) at increasing doses from 0.5 to 2.5 mcg (20-100 IU) per day. The rate of PSA increase (an indicator of disease progression) during treatment fell significantly compared to the rate before treatment in six of the subjects, suggesting a slowing of prostate cancer progression. In a related study, weekly dosing with calcitriol (at 20 IU per kilogram of body weight) increased median PSA doubling time in men who had been treated for prostate cancer. An increased PSA doubling time means that it takes longer for the PSA cancer marker to elevate (double), which is a favorable sign.

If my first blog didn’t convince you to start taking Vitamin D, this one ought to do the trick!