3. DETERMINE WHICH DIETARY SUPPLEMENTS YOU NEED

Now that you know what all of these vitamins can do, it's time to draw up a profile and see what you most likely need. While this list is a fantastic start, remember that you're playing with your health, so you should always let a doctor know when you are about to embark on a new vitamin regimen.

  • Smokers: If you insist on puffing away, you are probably in need of extra vitamin C. Smokers have lower vitamin C levels in their blood than nonsmokers and could benefit from supplementation of up to 500 mg a day.

  • Women:
    - Women are in particular need of stronger bones as they age, so you should start looking into a calcium supplement TODAY. Ideally, there should be an extra 1000mg of calcium in your diet every day. Calcium citrate and calcium carbonate are considered the best supplemental sources. To maximize the amount of calcium your body can absorb from the supplement, it is better to take no more than 500mg doses at a time with food. - If your favorite monthly visitor (that is our witty code for "menstruation") habitually reeks havoc and you experience extensive bleeding, consider an iron supplement. The extra iron can sometimes already be found in your multivitamin. - If you take birth control pills, you could be deficient in vitamins B6, C, folic acid and calcium. Luckily, a multivitamin will usually make up for the pill's interference. - Should you ever want to get pregnant (not tomorrow, but in 5 or 10 years) think about taking in extra folic acid. Research has found that having sufficient levels of folic acid during the first trimester of pregnancy does wonders to prevent birth defects such as cleft palate and neural tube defects. Or if you don't want to be bothered at this time, your OB/GYN will probably put you on prenatal vitamins once you decide it is time to start having those cute little babies (or loud little babies, depending on how helpful your husband is).

  • Vegetarians and Vegans: If you do not eat animal products such as meat and dairy, it is possible you are missing out on certain essential nutrients that carnivores have in abundance. Usually a multivitamin and mineral supplement will supply a plant eater with the needed vitamin B12, calcium, iron and zinc.

  • Fruit and Vegetable Haters: What did they ever do to you? Fruits and vegetables are the primary sources of most of the must have vitamins and your body prefers to absorb them via food. If you don't eat enough fruit and veggies, you might be deficient in vitamins B1, B6, C, calcium, magnesium and potassium. And funny thing, these are the ones that serve to protect your body from cancer and heart disease. The best solution: start nibbling regularly on bananas and broccoli spears. You should also be especially careful that your multivitamin has 100% of the RDA for these specific nutrients.

  • Dieters: Think about that grapefruit diet that was so en vogue a few years back. Odds are, if you're only eating grapefruit for weeks at time you are not getting the nutrients from any other food groups. Dieters and people who avoid entire food groups may require a multivitamin and mineral supplement to replace missing nutrients.

  • Daily Exercisers:Vitamins C, E and the mineral selenium could help your body recover from the stress of working out five or more times a week. For those who are really hard-core, you may want to supplement your multivitamin with separate supplements of extra vitamins C and E.

  • Those taking prescription medicines: Certain medications can interfere with the absorption of nutrients. Some medications and supplements, especially herbal supplements can be extremely dangerous if combined. It is best to talk to your doctor before adding any supplement to you drug regimen.

  • Heavy drinkers: You lush you. First, try rehab. After that, your body may need extra vitamin B6. Alcohol destroys the body's stores of B6 and if you become deficient in this nutrient you could develop anemia, icky skin conditions, kidney stones and start convulsing. Oh and your brain waves will become abnormal and you'll become extremely irritable.