Vitamins & Supplements Archive

Research we're watching

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Do you swallow a daily multivitamin, hoping to make up for a less-than-ideal diet? Sorry, but this strategy won't stave off heart disease, according to a study published online April 5, 2017, by JAMA Cardiology.

Previous research has also failed to find convincing evidence that a daily multivitamin lowers the risk of heart disease or cancer. But these studies didn't always account for the participant's dietary habits, which could potentially skew the results. In theory, people with poor diets might reap greater benefits from vitamins than those who eat healthier diets.

In the journals

Much research has shown that oxidative stress plays a key role in the development of neurodegenerative disorders, such as Alzheimer's and Parkinson's disease. As a result, antioxidant supplements like vitamin E and selenium have been proposed to prevent dementia. Yet a new study on older men published online March 20, 2017, by JAMA Neurology found no evidence they can help.

The Prevention of Alzheimer's Disease by Vitamin E and Selenium clinical trial included 7,540 men, average age of 67. Over a five-year period, the men were randomly assigned to receive 400 international units of vitamin E each day, 200 micrograms of selenium, both supplements, or a placebo. The supplements were stopped and 3,786 of these men agreed to be followed for an additional six years. They were routinely screened for cognitive problems and encouraged to see their doctor if the results suggested any kind of cognitive impairment.

It's easy enough to look up how much vitamin C or calcium you should get each day. It is also easy to read the back of a vitamin bottle to see just how much of a given vitamin or mineral the product provides. But how can you tell if what you eat — which should be your primary source of important nutrients — is giving you what you need?

One way is to focus on the big picture: eat a balanced diet that contains a variety of colorful fruits and vegetables, whole grains, beans, nuts, dairy products, seafood, lean meats, and poultry. Focus on nutrient-dense foods like these, which are packed with vitamins and minerals relative to the number of calories they deliver, and you should be fine.

Research we're watching

Dietary supplements made from red yeast rice contain substances called monacolins, which are similar to the active ingredient in cholesterol-lowering statin drugs. And like statins, red yeast rice products may cause rare but serious side effects, such as muscle injury and liver damage, as noted in a study published online January 19, 2017, by the British Journal of Pharmacology.

The study, based on a review of 13 years of patient data by Italian researchers, notes that people who can't tolerate statins often take red yeast rice supplements. But there are no studies testing the safety of red yeast rice compared with statins. In the United States, the FDA considers red yeast rice products that contain more than trace amounts of monacolins to be unapproved new drugs and therefore illegal to sell. Yet dozens of these unregulated products remain on the market.

It’s unclear why, but it appears that people with psoriasis are more likely to also suffer from diabetes.

When it comes to fighting high blood pressure, the average American diet delivers too much sodium and too little potassium. Eating to reverse this imbalance could prevent or control high blood pressure and translate into fewer heart attacks, strokes, and deaths from heart disease.

Normal body levels of potassium are important for muscle function. Potassium relaxes the walls of the blood vessels, lowering blood pressure and protecting against muscle cramping. A number of studies have shown an association between low potassium intake and increased blood pressure and higher risk of stroke. On the flip side, people who already have high blood pressure can significantly lower their systolic (top number) blood pressure by increasing their potassium intake when they choose to eat healthy foods.

After the death of Baltimore Orioles pitcher Steve Bechler more than 10 years ago, many questions arose about the safety of ephedra and the government's role in regulating the herb. Bechler died of heat stroke while taking ephedra, which occurs naturally in the Chinese herb ma huang. The speed-like drug contains the chemical ephedrine, an amphetamine-like compound closely related to adrenaline. Athletes and average people alike started taking ephedra when word started spreading about its ability to aid weight loss and increase energy and alertness.

But just because a supplement comes from natural sources doesn't make it safe. Ephedra can cause a quickened heartbeat and elevated blood pressure. Side effects include heart palpitations, nausea, and vomiting. More than 800 dangerous reactions have been reported with use of the herb. These include heart attacks, strokes, seizures, and sudden deaths. According to a study in the Annals of Internal Medicine, ephedra products make up only 1% of herbal supplement sales in the U.S., but they are responsible for 62% of herb-related reports to poison-control centers.

There's no good evidence that taking calcium supplements can harm your heart. Still, it's best to get this mineral from foods, not pills.

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For decades, doctors have encouraged people to consume plenty of calcium, a mineral best known for building strong bones. About 43% of people in the United States, including close to 70% of older women, take supplements that contain calcium. Concern about osteoporosis—the bone-weakening disease that leaves older adults prone to fracturing a hip, wrist, or other bone—has driven this trend.

Calcium also keeps your muscles, nerves, and blood vessels working well, and it's one of the key minerals involved in blood pressure control. With regard to heart disease, though, there's one potentially confusing aspect of the calcium story. A test researchers often use to look for early signs of heart disease is known as a coronary artery calcium (CAC) scan (see "Seeing calcium specks inside arteries"). There's no direct connection between the calcium you consume and the amount in your arteries. But in recent years, several studies have observed a link between the use of calcium supplements and a higher risk of cardiovascular disease.

 Scientific evidence doesn’t support taking cranberry extract to prevent urinary tract infections.