Too high levels of vitamin D in the blood may increase your risk of dying from a stroke, warns a study.

In terms of public health, a lack of vitamin D has long been a focal point and several studies have shown that too low levels can prove detrimental to our health.

The new study, therefore, suggests that the level of vitamin D in our blood should neither be too high nor to low.

"If your vitamin D level is below 50 or over 100 nanomol per litre, there is a greater connection to deaths," said Peter Schwarz, professor at the University of Copenhagen in Denmark.

The researchers studied the level of vitamin D in 247,574 people and analysed their mortality rate over a seven-year period. In that time 16,645 patients had died.

"We have looked at what caused the death of patients, and when numbers are above 100, it appears that there is an increased risk of dying from a stroke or a coronary," Schwarz added.

"In other words, levels of vitamin D should not be too low, but neither should they be too high. Levels should be somewhere in between 50 and 100 nanomol per litre, and our study indicates that 70 is the most preferable level," Schwartz explained.

That having too much vitamin D in our blood can be bad for our health has never been proven before, and it may have great influence on our future intake of nutritional supplements.

The study appeared in the Journal of Endocrinology and Metabolism.

If you thought that genetically modified (GM) soybean oil is any better than the normal soybean oil, you might be disappointed.

A study on mice by an Indian American researcher shows that genetically modified (GM) soybean oil is as unhealthy as conventional soybean oil. The study found that GM soybean oil too induces obesity, diabetes and fatty liver.

"The GM soybean oil has zero grams trans fat and more of the monounsaturated fats that are considered heart healthy," said lead researcher Poonamjot Deol of the University of California-Riverside.

"But it had not been tested for long term metabolic effects until our current study," Deol noted.

GM soybean oil, however, does not cause insulin resistance - the inability to efficiently use the hormone insulin.

The researchers compared the effects of both oils in experiments done in the lab on mice. Four groups of mice, each group comprising 12 mice, were given different diets for 24 weeks.

The control group received a low-fat diet (5 percent of daily calories from fat), while the other groups received a diet with 40 percent of daily calories from fat.

The fourth group had 41 percent of the saturated fat replaced with the GM soybean oil.

The mice fed a diet with either of the soybean oils had worse fatty liver, glucose intolerance and obesity than the group that got all their fat from coconut oil.

But the mice whose diet included the GM soybean oil had less fat tissue than the animals that ingested regular soybean oil.

"These results indicate that linoleic acid may contribute to insulin resistance and adiposity but that another as yet unidentified component of the soybean oil affects the liver and overall weight gain," Deol pointed out.

The study was presented at Endocrine Society's 97th annual meeting in San Diego.

High-salt diet is bad for health, say numerous studies, but a significant research now reveals that dietary salt could have a biological advantage -- defending the body against invading bacteria.

They found that a high-salt diet increased sodium accumulation in the skin of mice, thereby boosting their immune response to a skin-infecting parasite.

The findings suggest that dietary salt could have therapeutic potential to promote host defence against microbial infections.

Till now, high-salt is clearly known to be detrimental for cardiovascular diseases and stroke.

"Our study challenges this one-sided view and suggests that increasing salt accumulation at the site of infections might be an ancient strategy to ward off infections, long before antibiotics were invented," explained first study author Jonathan Jantsch, microbiologist at Universitatsklinikum Regensburg and Universitat Regensburg in Germany.

A clue to this mystery came when the team noticed an unusually high amount of sodium in the infected skin of mice that had been bitten by cage mates.

Intrigued by this observation, they examined the link between infection and salt accumulation in the skin.

The team found that infected areas in patients with bacterial skin infections also showed remarkably high salt accumulation.

Moreover, experiments in mice showed that a high-salt diet boosted the activity of immune cells called macrophages, thereby promoting the healing of feet that were infected with a protozoan parasite.

The researchers, however, urge caution over the potential health benefits of a high-salt diet.

"Due to the overwhelming clinical studies demonstrating that high dietary salt is detrimental to hypertension and cardiovascular diseases, we feel that at present our data does not justify recommendations on high dietary salt in the general population," Jantsch commented.

"Nevertheless, in situations where endogenous accumulation of salt to sites of infection is insufficient, supplementation of salt might be a therapeutic option," he emphasised.

Moving forward, the researchers will examine how salt accumulates in the skin and triggers immune responses and why salt accumulates in the skin of ageing adults.

"We also think that local application of high-salt-containing wound dressings and the development of other salt-boosting antimicrobial therapies might bear therapeutic potential," the authors concluded.

The paper appeared in the journal Cell Press.

It is well known that in the long run, eating fatty foods is bad for you and can increase your risk of having a stroke or heart attack, but as per a new study, a high-fat diet may actually be beneficial to your health and help to reduce heart attack damage.

WKeith Jones of Loyola University Chicago Stritch School of Medicine said that the study improves the understanding of the relationship between diet and health, adding learning about how fat, in the short run, protects against heart attacks could help in the development of better therapies

The study, which is not a license to eat a lot of cheeseburgers and ice cream, may provide new insight into the "obesity paradox": Obesity is a major risk factor for heart disease, but once a heart attack or heart failure does occur, moderately obese patients tend to live longer.

In the study, mice were given a high-fat diet (60 percent of calories from animal fat) before experiencing heart attacks. Mice that consumed a high-fat diet for either one day, one week or two weeks before the heart attack experienced about half as much heart damage as mice that ate a control diet. The benefit was greatest among mice that ate a high-fat diet for one week before the heart attack.

But in mice that ate a high-fat diet for six weeks, the protective effect disappeared. Further research is needed to understand why this is so; the reason may be due to the bad effects of a persistent high-fat diet, said Jones.

Proteins damaged by the heart attack are removed from heart cells as if they were garbage, thus increasing the chances the cells will survive. Acutely, a high-fat diet increases levels of a molecule in the blood that activates protective pathways in heart muscle. This increases the readiness of the "garbage trucks," which means that the cell becomes resistant to damage when the heart attack occurs as a result, more heart muscle survives.

First author Lauren Haar added that the study opens a new perspective on the acute effects of a high-fat diet and future work will determine whether these effects are linked to the obesity paradox and whether studying the mechanism can identify therapeutic targets for cardioprotection.

The study appears in the American Journal of Physiology - Heart and Circulatory Physiology.