Patti Landers, a dietitian from the University of Oklahoma Health Sciences Center, helps us breaks down what health remedies respected scientific studies say are helpful, conflicting and even potentially harmful.
The U.S. Prevention Task Force finds no sufficient evidence that vitamin D supplements prevent bone fractures in healthy adults. And the National Cancer Institute says it’s unclear whether the supplement will prevent cancer.
But vitamin D deficiencies are increasing in both children and adults, which are likely caused by poor diets, minimal sunlight exposure and sedentary lifestyles.
Doctors are concerned this deficiency is creating an increase in rickets, which is a softening of the bones in children that can lead to fractures. From the first few days of life through adolescence, the American Academy of Pediatrics recommends children have 400 international units of vitamin D per day, which is difficult to consume in food alone. Landers notes in this case, a supplement is a good option.
The U.S. Department of Agriculture recommends anyone at a higher deficiency risk — older adults, people with dark skin and those with less exposure to the sun — should take vitamin D supplements and/or consume fortified foods like milk.
Vitamin D also may prevent and help lessen symptoms of multiple sclerosis.
Sometimes, for severe deficiencies, more than the daily recommended amount is needed for a short period. Landers emphasizes that a doctor should monitor this intake to prevent a toxic dose.
There isn’t sufficient evidence proving fish oil supplements will help prevent heart disease, according to a 2012 study published in the Archives of Internal Medicine. However, researchers note more studies are needed.
A study in the American Journal of Epidemiology found high doses of fish oil may cause an increased risk for prostate cancer.
Landers said eating fish high in omega-3 (like wild salmon) twice a week is a better way to receive these nutrients, which could reduce cardiovascular disease and other chronic conditions.
Since adults older than 50 have a difficult time absorbing B12, the USDA recommended they eat fortified foods (like cereals) or take a supplement with 500 micrograms each day.
This vitamin helps keep nerve and blood cells healthy.
The National Center for Complementary and Alternative Medicine offers guidelines on what science has so far found about herbal remedies.
Evidence shows garlic may lower cholesterol and blood pressure levels. Studies are being conducted on its cancer-fighting properties.
There are still mixed results on whether green tea will prevent or slow the growth of certain cancers. There isn’t enough reliable evidence that says green tea will lower cholesterol and help with weight loss.
The Echinacea plant, used as a remedy for colds and other infections, also has inconclusive data.
When pregnant women take folic acid supplements, multiple studies show it helps reduce birth defects. Even if they’re not planning to become pregnant, women should take 400 to 800 micrograms daily, notes the National Institutes of Health. That way, if they do become pregnant, birth defects are prevented as early in the child’s development as possible.
Men shouldn’t take vitamin E supplements to reduce prostate cancer, according to a study conducted by the National Institutes of Health. There may be a slightly elevated risk to develop this cancer while taking these supplements.
Landers notes that taking a multivitamin that doesn’t exceed 100 percent of daily values is still a recommended part of a daily diet. However, it’s ultimately better to receive nutrients from balanced meals with fruits, vegetables, proteins, milk and whole grains.
There are “very few vitamin or mineral supplements that have been proven to be effective,” Landers said.
Anyone taking supplements should talk with their doctor since side effects are possible.