Vitamin Information Center

The August 20, 2008 edition of the Journal of the American Medical Association (JAMA) reported that B Vitamins did not work effectively to prevent death or cardiovascular events in a population of patients with coronary artery disease or aortic valve stenosis. In the wake of this report, we’ve seen a vocal response from industry, claiming that the study is not credible, as it failed to acknowledge elements that could have altered the conclusions presented.

The study, conducted from 1999 through 2006, on 3,096 patients in two Norwegian hospitals, was headed by Dr. Marta Ebbing, M.D. at Haukeland University Hospital. Patients’ concerns about taking B vitamins to ward off cardiovascular problems, but at the same time, increasing the chance of cancer, resulted in the study being stopped prematurely.

The study divided participants into one of four groups; daily oral treatment of folic acid plus vitamin B12 and vitamin B6; folic acid plus vitamin B12; vitamin B6 alone; or a placebo. The doses of vitamins used in the groups were 0.8 milligrams of folic acid, 0.4 milligrams of B12 and 40 milligrams of B6.

One of many questions that quickly arose in study feedback was whether beta blockers, statins and anti-platelets were used for the duration of the study. The participants started the study while in their mid-60’s, and more than 75 percent of them had already been using the above mentioned drugs for existing heart disease.

Another issue with the study was that Norway does not add folic acid to its wheat as is done in the US, ostensibly, because they do not believe that fortified foods are necessary. This, in turn, meant that any folic acid, B-6 or B-12 through supplementation or other food that participants may have been taking at home was not factored into the study, and could have affected the results. Analysts also believe that the study involved too narrow a section of the population, and could not provide a proper answer to what B vitamin does for healthy people, arguing that folic acid supplementation should be considered from a preventative standpoint only.

With so many variables unaccounted for in the study, one might wonder how it still went on for years without intellectual intervention. Hindsight though, is 20/20, and the missing factors are quite evident in retrospective analysis.

Dr. Andrew Shao, of the Council for Responsible Nutrition (CRN), in an interview with NPIcenter, explained that groups like the CRN “try to caution against over-interpretation of results and broad sweeping conclusions that you hear from some people.” Shao added “B vitamins may not work for people who already have heart disease, but these studies don’t answer the question of whether the healthy population, if they take B vitamins on a regular basis over the course of decades, may be at a lower risk for heart disease.”

Industry frequently complains, in cases like this, about study design.

Shao observed, “The study was actually pretty well designed. Every study has limitations. No matter what, you’re always going to have limitations to a study, and it’s important to identify those limitations; if you’re overly critical of them, that is a really difficult position to have because no one is ever going to conduct the absolute perfect study that answers every question that anyone would possibly want to ask in the world.”

Despite what seem like flaws in the study, it is important to remember that a be-all, end-all cure was not the final goal for Dr. Ebbing and colleagues. The study was to see if B vitamin use would lower homocystein levels and help those with existing heart disease, not simply if B vitamin use would prevent heart disease, and it seems to have done that.

“You have a tool box of prevention, and there are all kinds of tools in there that you can use to try and keep yourself healthy and avoid disease,” said Shao. “Using supplements is just one of these tools, among a whole bunch. It is not THE tool, it is A tool. You have other components such as diet, stress, exercise [and] genetics, which is a tool you can’t do anything with but you’ve still got it. Supplements are just one of those tools. If that’s your outlook and you understand it… that’s where the benefit will be seen.”

Chronic kidney disease patients may see their risk of death drop by one quarter if they take a form of vitamin D, a new study says.

In a study of more than 1,400 people with chronic kidney disease, those that were taking the drug calcitriol, a form of activated vitamin D, had a 26 per cent reduction in their risk of death versus those who were not on the drug. Overall, the patients on calcitriol had their risk of either death or dialysis due to a loss of kidney function fall by 20 per cent.

The study is published in the Journal of the American Society of Nephrology.

A healthy human body uses first the liver and then the kidneys to convert vitamin D obtained through diet and sunlight into an active form that the body can use. However, it is believed that patients with chronic kidney disease are unable to do complete the second step.

They are often prescribed activated vitamin D to help lower elevated levels of the parathyroid hormone, which can lead to a weakening of the bones. However, people with kidney disease often suffer from calcified, or stiff, blood vessels, which can lead to a host of cardiovascular problems. Vitamin D increases calcium levels in the blood, which doctors fear could exacerbate this problem.

“We did find that people who got the activated vitamin D drug did have a higher risk of having a high calcium level in the blood,” study author Dr. Bryan Kestenbaum of the University of Washington told Ctv.ca.

“But the overall amount of people that that happened to was relatively small, and the overall balance was that people who got the activated vitamin D drug survived longer.”

Kestenbaum speculated that vitamin D leads to decreased mortality rates because of its known ability to lower risk factors for cardiovascular disease, including high blood pressure, diabetes and inflammation.

He said that the next step in this field of research would be to conduct randomized clinical trials to confirm vitamin D’s effect on survival rates among patients with kidney disease.

The benefits of vitamin D have long been known. It’s central for healthy bones and preventing some cancers.

A recent study boosted D’s profile, saying people with a moderate vitamin D deficiency had a 60-percent increased risk of cardiovascular problems, and those with a severe deficiency a almost 100-percent risk.

Since we get vitamin D from the sun along with food, it seemed great news for those who like to catch some rays. But not so fast, says Judy Dowd, a physician’s assistant with Cotton-O’Neil Dermatology. She says one source says all you need is five to 10 minutes of sun exposure on the hands, arm and face, two to three times a week, to get enough sun exposure to get the vitamin D you need and metabolize it usefully.

That’s about a half hour total. Other health officials said up to two hours total a week is what’s needed. But you also get vitamin D from food. Dowd says it is milk, cereals, breads and other foods are fortified with it and it’s also in eggs and liver.

Dowd advocates minimal sun exposure, so that you get enough vitamin D without adding to the risk sun exposure poses. She says it can cause early signs of aging, like wrinkles. It can also impact the immune system and cause skin cancers.

Dowd says it’s projected there’ll be 1.3 million new cases of skin cancer in the next couple years. She says many health experts attribute this to the increased use of tanning beds. As for tanning beds and vitamin D, she says we get vitamin D from UVB rays, not UVA rays, and most tanning beds use only UVA rays.

The number of skin cancers continues to climb and successful treatment means catching it early. The Cotton-O’Neil Cancer Center will have free skin cancer screenings Saturday, April 26th. It’s free, but you do have to register for an appointment by calling HealthConnections at 785-354-5225.