Some docs award vitamin D an ‘E’
Last week, we explained that vitamin D can assist with reducing the effects of Alzheimer’s disease. This week we take a closer look at what dissenting studies have found.
By Jasminee Sahoye
Over the years vitamin D has been gaining a reputation as a wonder vitamin that offers protection against some cancers, bone-weakening osteoporosis, heart attack, Alzheimer’s disease and other chronic conditions. However, two studies show different results according to the Harvard Medical Publications.
In BMJ, a weekly peer-reviewed publication and one of the world’s oldest general medical journals, Evropi Theodoratou, a research fellow at the University of Edinburgh, along with other researchers evaluated the results of 268 previous studies of vitamin D.
What they found were “highly convincing evidence of a clear role of vitamin D does not exist for any outcome but associations with a selection of outcomes are probable.” In other words, no solid proof taking vitamin D helps.
In another BMJ article, a study led by Rajiv Chowdhury, a cardiovascular epidemiologist at the University of Cambridge, showed that low blood levels of vitamin D are linked to increased risks of dying prematurely from cardiovascular disease, cancer, and other causes. But whether supplementation with vitamin D can help people live longer and healthier requires more study.
According to Dieticians of Canada, vitamin D is often called the ‘sunshine’ vitamin, as our skin is able to make the vitamin when exposed to the sun. Vitamin D is best known for its role in keeping bones and teeth healthy. Recent research suggests that vitamin D may also have benefits in fighting infections, reducing heart disease risk factors, and preventing diabetes, multiple sclerosis and some types of cancers (especially colorectal cancer). However, more research is needed to fully understand the role of vitamin D in these conditions.
Many medical experts say they would advise their patients to get the amount of vitamin D recommended by the Institute of Medicine which are 600 IU of vitamin D a day for everyone ages one to 70 and 800 IU of vitamin D a day for those 71 and older.
Although food is usually the best way to get vitamins, only a few contain vitamin D such as salmon, tuna, sardines, milk, fortified cereals and some types of mushroom. They can give you more than 100 IU per serving.
But the best way to get vitamin D is from the sun experts say. Getting 10 to 15 minutes of sunlight on your face, arms, back or legs without sunscreen a few times a week is enough to generate your body’s vitamin D needs for a week. But too much exposure to the sun causes skin cancer.
“If you rarely get out in the sun, or just aren’t certain you are getting 600 to 800 IU of vitamin D a day, taking a supplement containing 400 to 1,000 IU is safe, inexpensive insurance,” Dr. Howard LeWine, wrote in the Harvard Health Publications.
Here is how vitamin D is said to aid in certain types of diseases:
Multiple Sclerosis: Multiple sclerosis (MS) rates are much higher far north (or far south) of the equator than in sunnier climes and researchers suspect that chronic vitamin D deficiencies may be one reason why. One prospective study to look at this question found that among white men and women, those with the highest vitamin D blood levels had a 62% lower risk of developing MS than those with the lowest vitamin D levels. The study didn’t find this effect among black men and women, most likely because there were fewer black study participants and most of them had low vitamin D levels, making it harder to find any link between vitamin D and MS if one exists.
Type 1 Diabetes: Type 1 diabetes is another disease that varies with geography—a child in Finland is about 400 times more likely to develop it than a child in Venezuela. Evidence that vitamin D may play a role in preventing type 1 diabetes comes from a 30-year study that followed more than 10,000 Finnish children from birth: Children who regularly received vitamin D supplements during infancy had a nearly 90% lower risk of developing type 1 diabetes.
The Flu and the Common Cold: The flu virus is prevalent in the winter. This led a British doctor to hypothesize that a sunlight-related “seasonal stimulus” triggered influenza outbreaks. More than 20 years after this initial hypothesis, several scientists published a paper suggesting that vitamin D may be the seasonal stimulus.
“Among the evidence they cite: The active form of vitamin D tempers the damaging inflammatory response of some white blood cells, while it also boosts immune cells’ production of microbe-fighting proteins.”