We tend to get overwhelmed just by standing in the vitamin aisle, so we asked Joan Salge Blake, MS, RD, LDN, a spokesperson for the Academy of Nutrition and Dietetics, to break down the letters for us.
Vitamin A: "This is needed for vision, cell differentiation and a healthy immune system," Salge Blake says. "You can get vitamin A from beta-carotene, which is found in carrots, cantaloupe and a lot of plants. Beta-carotene gives you a two-for-the-price-of-one effect, because it's a disease-fighting antioxidant, too."
Vitamin B: "There are multiple Bs and they're involved in metabolism and energy production. They also protect the nerves and prevent anemia," Salge Blake adds. "Pregnant women and women of childbearing age need adequate folic acid [to support spine and brain development]. Older people produce less hydrochloric acid in their stomachs and can't process B12 properly. Vegans need a B12 supplement, because it's only found in meats."
Vitamin C: "C is one of the most overused supplements," she says. "People think that because the body excretes excessive vitamin C in the urine that you can't overdo it. But too much of any vitamin can be problematic. With all vitamins, I say, 'Some is good, more is not necessarily better.'"
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Vitamin D: "This is essential for bone health. We get it through sunshine, but baking in the sun causes skin cancer. ... People who spend a lot of time indoors or who don't drink milk might need a supplement."
Vitamin E: "We know it best as an antioxidant. It protects cell membranes. We get it from a lot of vegetable oils and nuts."
Vitamin K: "This is the blood-clotting vitamin," Salge Blake says. "It's found in green vegetables, and if you eat the recommended four and a half cups of fruit and vegetables a day it should fulfill your needs."
Top-rated supplement brands on consumer satisfaction:
Catalogue/Internet brand: Swanson
Direct-selling (MLM) brand: Nutrilite
Discount/warehouse brand: Kirkland (Costco)
Grocery store brand: Trader Darwin (Trader Joe's)
Health care practitioner brand: Pure Encapsulations
Health food store brand: Nutricology
Mass market multicategory brand: Biotivia
Mass-market single-category brand: Citracal
Pharmacy brand: CVS
Vitamin store brand: Vitamin World