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 A number of recent studies looked at vitamin D and various diseases. All showed benefits of higher vitamin D levels in the blood: lower rates of cancer incidence, improved heart function in those with heart failure, lower rates of leukemia incidence, lower rates of breast cancer, and less aggressive breast and prostate cancer. However, one study found no benefits to vitamin D supplementation during pregnancy and the child's asthma risk. Older studies found low levels of vitamin D linked to higher risk of premenopausal breast cancer, and also to thicker melanomas at diagnosis (the thinner the melanoma, the better the prognosis).

Everyone agrees that sunshine is an excellent source of vitamin D, but there is still disagreement over what are the best daily vitamin D supplement dosages, or even what are optimal levels of vitamin D in the blood (measured as serum 25-hydroxyvitamin D or 25(OH)D). In 2010, the Institute of Medicine (IOM) concluded that levels lower than 12 ng/ml represented a vitamin D deficiency and recommended a target of 20 ng/ml, which could be met in most healthy adults (ages 19 to 70) with 600 International Units of vitamin D each day. Since then most researchers have argued for higher blood serum levels: most agreeing that over 30 ng/ml is best, while some advocating 50 ng/ml or more. But even what's too high (and could cause problems) is debated. Many vitamin D supporters now advocate taking 800 to 1,000 IUs of vitamin D daily (some say up to 4000 IUs daily is OK). Remember to look for vitamin D3 supplements, not D2.

This study found that higher levels of vitamin D (measured as serum 25(OH)D) are better, with 25(OH)D concentrations of at least 40 ng/ml best to reduce cancer risk (all types of cancer). From Medical Xpress: Higher levels of vitamin D correspond to lower cancer risk, researchers say

Researchers at University of California, San Diego School of Medicine report that higher levels of vitamin D - specifically serum 25-hydroxyvitamin D - are associated with a correspondingly reduced risk of cancer. The findings are published in the April 6, online issue of PLOS ONE.

Garland and his late brother, Frank, made the first connection between vitamin D deficiency and some cancers in 1980 when they noted populations at higher latitudes (with less available sunlight) were more likely to be deficient in vitamin D, which is produced by the body through exposure to sunshine, and experience higher rates of colon cancer. Subsequent studies by the Garlands and others found vitamin D links to other cancers, such as breast, lung and bladder.

The new PLOS ONE study sought to determine what blood level of vitamin D was required to effectively reduce cancer risk....The only accurate measure of vitamin D levels in a person is a blood test....Cancer incidence declined with increased 25(OH)D. Women with 25(OH)D concentrations of 40 ng/ml or greater had a 67 percent lower risk of cancer than women with levels of 20 ng/ml or less.

Garland does not identify a singular, optimum daily intake of vitamin D or the manner of intake, which may be sunlight exposure, diet and/or supplementation. He said the current study simply clarifies that reduced cancer risk becomes measurable at 40 ng/ml, with additional benefit at higher levels. "These findings support an inverse association between 25(OH)D and risk of cancer," he said, "and highlight the importance for cancer prevention of achieving a vitamin D blood serum concentration above 20 ng/ml, the concentration recommended by the IOM for bone health."

From Science Daily: Vitamin D improves heart function, study finds

A daily dose of vitamin D3 improves heart function in people with chronic heart failure, a five-year research project has found. The study involved more than 160 patients who were already being treated for their heart failure using proven treatments including beta-blockers, ACE-inhibitors and pacemakers.

Participants were asked to take vitamin D3 or a dummy (placebo) tablet for one year. Those patients who took vitamin D3 experienced an improvement in heart function which was not seen in those who took a placebo....In the 80 patients who took Vitamin D3, the heart's pumping function improved from 26% to 34%. In the others, who took placebo, there was no change in cardiac function.

Disappointing results. From Medscape: Vitamin D Disappoints: Prenatal Supplementation and Childhood Asthma

Two recent clinical trials examined maternal supplementation with vitamin D and postpregnancy offspring outcomes for asthma and wheezing....However, with respect to preventing asthma in offspring, there is no clear evidence for vitamin D supplementation in pregnant women.

From PLOS ONE: Vitamin D Deficiency at Melanoma Diagnosis Is Associated with Higher Breslow Thickness

Vitamin D deficiency at the time of melanoma diagnosis is associated with thicker tumours that are likely to have a poorer prognosis. Ensuring vitamin D levels of 50 nmol/L or higher in this population could potentially result in 18% of melanomas having Breslow thickness of <0.75 mm rather than ≥0.75 mm.

Reported in 2013. From Medical Express: Low vitamin D levels linked to high risk of premenopausal breast cancer

A prospective study led by researchers from the University of California, San Diego School of Medicine has found that low serum vitamin D levels in the months preceding diagnosis may predict a high risk of premenopausal breast cancer. The study of blood levels of 1,200 healthy women found that women whose serum vitamin D level was low during the three-month period just before diagnosis had approximately three times the risk of breast cancer as women in the highest vitamin D group. 

A 2011 meta-analysis by Garland and colleagues estimated that a serum level of 50 ng/ml is associated with 50 percent lower risk of breast cancer. While there are some variations in absorption, those who consume 4000 IU per day of vitamin D from food or a supplement normally would reach a serum level of 50 ng/ml.

More research on the benefits of exercise. From Medical Xpress:

An hour of moderate exercise a day may decrease heart failure risk

In a new study reported in the American Heart Association journal Circulation: Heart Failure, researchers say more than an hour of moderate or half an hour of vigorous exercise per day may lower your risk of heart failure by 46 percent. Heart failure is a common, disabling disease that accounts for about 2 percent of total healthcare costs in industrialized countries. Risk of death within five years of diagnosis is 30 percent to 50 percent, researchers said.

Swedish researchers studied 39,805 people 20-90 years old who didn't have heart failure when the study began in 1997. Researchers assessed their total- and leisure time activity at the beginning of the study and followed them to see how this was related to their subsequent risk of developing heart failure. They found that the more active a person, the lower their risk for heart failure. 

From Medical Xpress:

Workers who exercise lower health risks, cost less

Get moving: just 20 minutes of exercise a day dramatically lowers the risk of diabetes and heart disease, even for employees with a high risk of developing those conditions.

A University of Michigan study looked at the impact of exercise on 4,345 employees in a financial services company that had just started a workplace wellness program. Roughly 30 percent of employees were high risk and suffering from metabolic syndrome, a dangerous cluster of risk factors associated with diabetes and heart disease. Overall, about 34 percent of U.S. adults have metabolic syndrome.

The study found that when the high-risk employees accumulated the government-recommended 150 minutes of moderate-intensity exercise a week, their health care costs and productivity equaled that of healthy employees who didn't exercise enough, said Alyssa Schultz, a researcher at the Health Management Research Center in the U-M School of Kinesiology.

"It was a real surprise, the level of protection physical activity gave to people with metabolic syndrome," Schultz said. 

Research done in mice, but may apply to humans. From Science Daily:

How physical exercise protects the brain from stress-induced depression

Physical exercise has many beneficial effects on human health, including the protection from stress-induced depression. However, until now the mechanisms that mediate this protective effect have been unknown. In a new study in mice, researchers show that exercise training induces changes in skeletal muscle that can purge the blood of a substance that accumulates during stress, and is harmful to the brain.

"In neurobiological terms, we actually still don't know what depression is. Our study represents another piece in the puzzle, since we provide an explanation for the protective biochemical changes induced by physical exercise that prevent the brain from being damaged during stress," says Mia Lindskog, researcher at the Department of Neuroscience at Karolinska Institutet.

 

But I wonder if the results would be different if the only processed meat (cold cuts, salami, prosciutto) you ate came from antibiotic, hormone, additive, and nitrate-free meat. From Science Daily:

Processed red meat linked to higher risk of heart failure, death in men

Men who regularly eat moderate amounts of processed red meat such as cold cuts (ham/salami) and sausage may have an increased risk of heart failure incidence and a greater risk of death from heart failure. 

Processed meats are preserved by smoking, curing, salting or adding preservatives. Examples include cold cuts (ham, salami), sausage, bacon and hot dogs."Processed red meat commonly contains sodium, nitrates, phosphates and other food additives, and smoked and grilled meats also contain polycyclic aromatic hydrocarbons, all of which may contribute to the increased heart failure risk," said Alicja Wolk, D.M.Sc., senior author of the study and professor in the Division of Nutritional Epidemiology at the Institute of Environmental Medicine, Karolinska Institutet in Stockholm, Sweden. "Unprocessed meat is free from food additives and usually has a lower amount of sodium."

The Cohort of Swedish Men study -- the first to examine the effects of processed red meat separately from unprocessed red meat -- included 37,035 men 45-79 years old with no history of heart failure, ischemic heart disease or cancer. 

After almost 12 years of follow-up, researchers found:  - Men who ate the most processed red meat had more than a 2-fold increased risk of death from heart failure compared to men in the lowest category. - For each 50 gram (e.g. 1-2 slices of ham) increase in daily consumption of processed meat, the risk of heart failure incidence increased by 8 percent and the risk of death from heart failure by 38 percent. - The risk of heart failure or death among those who ate unprocessed red meat didn't increase.

"To reduce your risk of heart failure and other cardiovascular diseases, we suggest avoiding processed red meat in your diet, and limiting the amount of unprocessed red meat to one to two servings per week or less," said Joanna Kaluza, Ph.D., study lead author and assistant professor in the Department of Human Nutrition at Warsaw University of Life Sciences in Poland. "Instead, eat a diet rich in fruit, vegetables, whole grain products, nuts and increase your servings of fish."