Of all the concerns about how to eat right and stay healthy, which supplements to take – if any – may be one of the most baffling. No recent incident better illustrates the confusion than conflicting headlines published on the same day in the 'Wall Street Journal' and 'The New York Times': "Triple That Vitamin D Intake, Panel Prescribes" and "Extra Calcium and Vitamin D Not Necessary, Report Says," respectively. Although both newspapers accurately reported a new standard by the Institute of Medicine (IOM) that triples the recommended daily amount of D, the disparity is telling.

In general, you can assume that most supplements make exaggerated claims about what they do. "Because there's such a prevailing desire for a quick fix – a silver bullet for health issues – the supplements industry can get its marketing hype well ahead of the science," says David Katz, founder of Yale University's Prevention Research Center. But that doesn't mean that supplements shouldn't be part of your diet. Here are three that many doctors – supported by reams of sound studies – say every man should take.

Vitamin D
Ignore what you've read about new dosing for D: Although the IOM raised the recommended daily amount (RDA) to 600 international units (IU), many doctors, including Andrew Weil, founder of the Arizona Center for Integrative Medicine, say the standard is still too low. Vitamin D is essential to the body for absorbing calcium and repairing bone, Weil says, but higher amounts – 1,000 to 2,000 IU of D daily – are critical for disease prevention, too. "The IOM's recommendation for vitamin D is very conservative and lags behind research," he says. More than 200 medical studies are published on D every month, says Joseph Pizzorno Jr., a former member of the White House Commission on Complementary and Alternative Medicine Policy, many with strong evidence showing the vitamin can help reduce the risk of cardiovascular disease and some cancers. Among the most persuasive are a recent study that found that people with low D levels have more than twice the risk of heart attack or stroke and three major Harvard University studies that link lowered levels to colorectal and pancreatic cancers. Evidence continues to show that the nutrient can also help fight type 2 diabetes, cognitive decline, depression, and arthritis.

Why can't you get enough D from food or sunlight, which naturally produces the nutrient in the body? Few foods – mainly D-fortified milk and fatty fish like salmon and tuna – contain the vitamin, and most Americans don't consume these often enough to generate high levels. We also spend the majority of our time inside and often use sunscreen when out, limiting natural production. Also, most of us live too far north to get enough sun during the winter to generate adequate amounts of D. The result is that more than half of the U.S. is D-deficient, according to the Centers for Disease Control and Prevention.

How to take it: Vitamin D comes in two forms: D2, which is plant-based, and D3, or what the body makes from food and sun. James Dowd, CEO of the Arthritis Institute of Michigan and author of 'The Vitamin D Cure', recommends D3, three times more potent than D2.

Doctors recommend: Carlson Labs Ddrops ($29), Vital Nutrients Vitamin D3 ($14)

Omega-Fatty Acids
Omega-3 fatty acids, one of the most popular supplements today, are essential to building cell membranes. Because the body doesn't naturally produce omega-3s, we have to get them through diet, but few foods contain significant amounts. Fatty fish is high in omega-3s – a half fillet of wild salmon contains up to 4,000 milligrams – but if you don't eat at least two servings weekly or consume flaxseeds, nuts, or canola oil daily, you're most likely deficient.

Doctors say omega-3 supplements are key not only to cell health but also to keeping the heart healthy by reducing blood triglycerides, which can cause arteries to harden. The evidence is so pervasive that in 2004 the FDA approved one of its rare health claims, allowing manufacturers to print on everything from fortified juice and eggs to chocolate bars that "omega-3s may lower the risk of coronary heart disease." Since then, more research supporting the claim has been conducted, including a 2008 Mayo Clinic study of 32,000 people showing that those who supplemented with 850 to 1,800 mg of omega-3s daily have up to 45 percent reduced risk of cardiovascular problems like heart attacks, and that taking a combination of supplemental omega-3s and statin drugs is more effective at treating heart disease than statins alone. Research continues to mount showing omega-3s can also help protect against arthritis, depression, dementia, and other cognitive problems. "Most Americans are deficient in omega-3s, which may account for the rise of asthma, coronary heart disease, many cancers, and neurodegenerative disease," Weil says.

How to take them: Most experts say to take 1,000 to 2,000 mg daily. Look for a supplement that delivers at least 500 mg each of EPA and DHA, the two active fatty acids in omega-3s. Fish oil is better than plant-derived supplements, which don't contain both acids.

Krill, a shrimp-like crustacean, has become a trendy oil source, as larger fish like cod and herring can be contaminated with mercury. But there's growing concern that krill is being overfished, endangering whales that rely on it for food. Doctors also argue that the process used to extract oil from larger fish is so sophisticated that contaminants don't end up in supplements.

Doctors recommend: Nordic Naturals Ultimate Omega ($28), OmegaBrite 100% Natural Advanced Omega-3 ($23)

The Centers for Disease Control and Prevention reports that only a quarter of Americans eat the recommended number of vegetables every day and that only a third consume enough fruit. "The reason they're called vitamins is that they're vital to life, yet 92 percent of Americans are deficient in one or more essential vitamins and minerals because they don't eat enough fruits, vegetables, and other whole foods," says Mark Hyman, chairman of the Institute for Functional Medicine. While there's little research showing that multivitamins can treat specific diseases, Weil says the supplements can be important as a type of nutritional mortar, filling in the chinks caused by a less-than-perfect lifestyle.

How to take them: Scan labels to check if a multi contains 100 percent of the RDA of the 21 essential nutrients: vitamins A, C, D, E, K, and B (including thiamin, riboflavin, niacin, B6, B12, pantothenic acid, biotin, folate, and choline) and minerals calcium, chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorous, selenium, zinc, potassium, sodium, and chloride. A quicker screening method, says Dowd, is to look to see if a multi has 100 percent of the RDA for vitamin K. Most don't, so if you find one that does, it's usually a good bet.

Only so many nutrients can fit into a multivitamin, so if a pill contains everything from açai to zeathanthin, chances are it doesn't have adequate dosages of every ingredient, says Andrew Shao, senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition. Instead, stick mainly to the essentials and don't go too high above the Daily Value (DV). "Some companies put in an absurd number of nutrients when there is no data to support it," says Steven Kaplan, director of the Iris Cantor Men's Health Center at New York-Presbyterian Hospital/Weill Cornell Medical Center. "Most of those ingredients just wind up in the toilet, literally, because your body doesn't need that much." That said, don't look to your multi for adequate vitamin D. If a multi provides less than 1,000 IU – and most do – you'll still need a D supplement.

Doctors recommend: Enzymatic Therapy Doctor's Choice Men ($25), Ray & Terry's Two-a-Day Multiple ($20)