If you're in your 40s, add these (along with the base plan and supplements for the 30s):

1) Coenzyme Q10:
This little gem provides energy for the heart and helps produce ATP, the major energy source for cells. It's also crucial if you're on cholesterol-lowering medications called statins. "Statins can significantly slow or reduce coenzyme Q10, which your heart needs," Bowden says. Even if you're not on statins, you could give your heart a healthy boost by taking 30 to 60 grams a day. Otherwise, if you're taking statins, the dose may be higher, perhaps 100 milligrams or more; talk with your physician, although Bowden warns that many aren't well-versed in nutrition.

2) Saw Palmetto:
If you're waking up to go to the bathroom 100 times a night, don't be alarmed. "Your prostate gland grows as you age and puts pressure on your bladder," Bowden says. To remedy that, take 160 milligrams of saw palmetto twice daily.

3) Alpha Lipoic Acid:
As you age, your body's ability to utilize glucose becomes impaired. But alpha lipoic acid can help regulate blood sugar, especially if you're prediabetic. It also aids in brain health, acts as a super-antioxidant by recycling vitamin C and E, and can be beneficial for the liver. Bowden recommends taking about 100 milligrams a day.

If you're in your 50s, add these (along with the base plan and supplements for the 30s and 40s):

1) Acetyl l Carnitine, Phosphitadyl Serine, and GlyceroPhosphoCholine (GPC):
Although they're tongue twisters, these nutrients are vital to brain health, Bowden says. Take about 750 to 1000 mg of acetyl l carnitine, 150 to 300 mg of phosphitadyl serine, and 450 to 600 mg of GPC daily.

2) Selenium:
Selenium should be in your multivitamin. But to reach 200 micrograms daily, which Bowden recommends, you probably need to supplement, as most multivitamins usually contain only 50 or 100 micrograms.

3) Ginkgo Biloba:
This powerful antioxidant helps protect brain cells from damage. Take 240 to 360 milligrams a day, Bowden says.

4) B12:
As you age, decreasing dietary intake and absorption make it tough to get all of your B vitamins, including B12, B6, and folate, all of which are crucial for the metabolism of carbohydrate, protein, and fat. Of those, though, B12 may deserve the most attention. "Although most adults over 50 eat the major B12 source, animal protein, the body has a challenge releasing it from food," Anding says, adding that some studies suggest that up to 30 percent of adults over 50 have blood levels of B12 that are too low. Ask your doctor to check your B12; if you're low, you may need to supplement.

More Supplements You Need

If You're Trying to Lose Weight
There are a few pills out there that may help—when paired with exercise and cutting calories, of course. Roberta Anding, M.S., R.D., a spokesperson for the American Dietetic Association suggests taking a green tea supplement (or simply drinking the liquid stuff). The nutrient contains an antioxidant called EGCG, which may help burn excess body fat. Supplemental doses of calcium and fiber may help as well; studies have linked both to weight loss.

If You're in a High-Stress Job
If you can't shed stress through exercise, yoga, or even meditation, try these three supplements: Rhodiola rosea (100 to 300 milligrams), which appears to boost some men's mental state; 5-HTP (100 to 300 milligrams), which helps produce more of that feel-good hormone serotonin, increasing mood and improving sleep; and B6 complex (100 milligrams), which boosts serotonin, as well. Carlson recommends taking all three daily during stressful times.

If You're Playing a Sport
Creatine should help you to maximize the benefits of strength training. Also consider B-alanine, which acts as a buffer to lactic acid, helping you feel better and train harder. The minimal useful dose is 3.2 to 4.5 grams per day. An essential amino acid called leucine may help with muscle recovery if you take one gram a day. And to give you a little oomph when your motivation is low, many experts also recommend caffeine, taken either in supplement or beverage form.