Based on the latest studies, here are ten you can skip:
Vitamin A: Excess amounts accumulate and can be toxic. Too much A can blur vision, cause headaches and vomiting, and also lead to liver, bone and central nervous system problems, among others.
RDA*: Men - 900 mcg. Women - 700 mcg. One 7-inch carrot has 600 mcg. Other food sources: fortified cereals, dark leafy greens, fruits, sweet potatoes.
Beta Carotene: The body converts this into vitamin A. Supplementation is not recommended for the general public and should be avoided especially by smokers, who have a greater risk of lung cancer with regular use. Another recent study found that high levels of beta carotene in the blood were linked to three times the risk of aggressive prostate cancer.
RDA: None established. You can get what you need from dark green and orange fruits and veggies.
Vitamin C: There’s no conclusive evidence that it prevents colds, heart disease, cataracts or cancer.
RDA: Men - 90 mg. Women - 75 mg. Smokers need an extra 35 mg. A glass of OJ will give you almost all you need.
Vitamin E: Large doses can thin the blood and may increase the risk of hemorrhagic stroke in those with uncontrolled blood pressure. Has not been proven to protect the heart or prevent cancer.
RDA: 15 mg. An ounce of dry-roasted almonds will provide almost half your daily needs.
Selenium: Most Americans get enough of this trace mineral in their diet. One new study suggests that adding more via a pill may increase the risk of developing type 2 diabetes.
RDA: 55 mcg. Grab a tuna sandwich or a handful of Brazil nuts instead.
Folic acid: It’s a must during pregnancy to help prevent birth defects, but recent studies show no real effect for the rest of us against heart disease, cancer or depression. The connection between folate and reduced risk of Alzheimer’s is not yet conclusive either.
RDA: 400 mcg. Find it in dark green leafy vegetables, fortified cereals and whole-grain breads.
Niacin: This B vitamin can be used to treat high cholesterol, but only under a doctor’s supervision due to the risk of potentially serious side effects, including liver damage.
RDA: Men - 16 mg. Women - 14 mg. A multivitamin gives you 20 mg. Some products will give you 500 mg. Stick to meat, fish, poultry, nuts and eggs instead.
Lycopene: Two studies, one by the FDA, recently concluded that consuming lycopene as a supplement or in rich food sources, such as tomatoes, does not offer strong cancer-fighting protection, as was previously promoted.
RDA: None established. You should still eat tomatoes (tomato sauce is even better) because they’re full of other important nutrients.
Iron: Only women who are pregnant or have heavy periods, as well as people with diagnosed deficiency disorders such as anemia, need extra amounts of this mineral. Iron supplements can interact with meds, other dietary supplements and food, and can worsen conditions like ulcers.
RDA: Women over 50 and all men - 8 mg. Women ages 19 to 50 - 18 mg. Red meat, poultry, fortified cereals, dried beans and lentils, and dark leafy greens are good sources.
Zinc: High doses can interfere with how the body metabolizes copper and iron, may weaken the immune system and may also reduce levels of HDL (good) cholesterol. Studies are mixed about its effect on the common cold. Zinc supplements can also interact with certain drugs, including some antibiotics, blood pressure medications and NSAIDs.
RDA: Men - 11 mg. Women - 8 mg. Meat and poultry are high in zinc; vegetarians should eat plenty of grains, beans, nuts, lentils and dairy products.
*RDA is for general adult population. Some groups, such as pregnant or breast-feeding women, need more.
