How much do you need? Men: 90 mg. Women: 75 mg. (Smokers should add an extra 35 mg.)
Why you need it: Important for wound healing; boosts immune system; required for growth and repair of tissues in all parts of body.
Good to know: No studies confirm that vitamin C prevents colds, although it may shorten the length of a cold; excessive amounts can lead to upset stomach and diarrhea.
Food sources: Citrus fruits, tomatoes, kiwi, strawberries.
How much do you need? Ages 51-70: 600 IU. Age 71+: 800 IU
Why you need it: Vitamin D helps the body absorb calcium; may protect against heart disease, cancer, diabetes and several autoimmune diseases
Good to know: Very high levels of vitamin D (above 10,000 IU a day) may cause kidney and tissue damage. Some blood test results for vitamin D may lead to an inaccurate diagnosis of vitamin D deficiency.
Food sources: Sun exposure provides the body's main supply of vitamin D; fatty fish, fortified milk and juices also contribute.
How much do you need? Men and women: 15 mg
Why you need it: Vitamin E helps protect cells from damage; may reduce the risk of developing cancer, heart disease and other chronic diseases, but further research is needed.
Good to know: If you take a blood thinner, talk to your doctor before taking supplements; vitamin E increases bleeding risk.
Food sources: Vegetable oils, nuts, fruits, vegetables.
How much do you need? Men and women: 400 mcg
Why you need it: A B vitamin, folic acid helps form red blood cells and produce DNA.
Good to know: High levels may mask vitamin B12 deficiency, especially in older adults. Recent research, suggests that for women, folic acid along with vitamins B6 and B12 may reduce the risk of developing age-related macular degeneration.
Food sources: Enriched cereals, whole-grain breads, dark, leafy vegetables.
How much do you need? Men: 120 mcg. Women: 90 mcg
Why you need it: Vitamin K helps blood clot properly and helps maintain strong bones in older men and women.
Good to know: Can dilute the effect of blood thinners, so talk to your doctor if you take Coumadin (warfarin) or other blood thinners.
Food sources: Plant oils, green vegetables, cabbage, cauliflower.