How Dietary Supplements Work

Food vs. Dietary Supplements
In general, it's better to get your vitamins from food than from a pill. Food contains other nutrients and phytochemicals not found in supplements. woraput/Getty Images

Foodies, rejoice: Experts say it's best to get your vitamins and minerals from fresh, tasty food rather than supplements. The problem is, people (especially Americans) aren't eating all that much fresh food, instead favoring processed foods, refined grains and added sugars, all of which have little nutritional value. If you're elderly, the problem is compounded because aged bodies can't absorb nutrients as easily as young ones can. Plus, seniors often eat less food overall due to dampened appetites. In the end, many people simply are unable to get the nutrients they need from the food they eat.

Dietary supplements can help fill gaps in your diet if you don't eat a lot of nutritious food. But before you head to the supplement aisle, experts recommend first trying to eat healthier. That's because, it's not just the specific supplement you're missing — it's also how you're receiving it that matters.

Food contains many valuable nutrients as well as phytochemicals. Phytochemicals are plant chemicals that have properties that protect you from disease. The phytochemical allicin, for example, is found naturally in garlic and helps fight bacteria, while isoflavones in soy and could lessen menopausal symptoms in some women. Phytochemicals may also enhance bioavailability, which is the amount of the vitamin or mineral that your body is able to absorb. But phytochemicals are not included in supplements [sources: Berkeley Wellness, Phytochemicals].

Furthermore, food contains nutrients that help each other out. Down a frosty glass of milk and you'll be gifted not just vitamin D and various nutrients and phytochemicals, but also lactose, which helps your body absorb calcium and magnesium. If you simply took a supplement, all you'd get is the vitamin D. Also, if you take too much vitamin D (or any other supplement), it might affect your body's ability to properly absorb various nutrients.

Finally, while the nutrients in supplements and food may be chemically identical, that doesn't necessarily mean they will act the same way in your body. A study by researchers at the University of Pennsylvania School of Medicine showed the valuable Omega-3s in fatty fish were better able to maintain proper blood pressure in mice than the Omega-3 in fish oil supplements. In the study, the scientists observed how one of the fish fatty acids, docosahexaenoic acid (DHA), lowered blood pressure by dilating blood vessels at ion channels. But the DHA ethyl ester, which most fish oil supplements contain, did not dilate the blood vessels at these sites. Even worse, the DHA ethyl ester appeared to fight with the natural DHA [source: Science Daily].

So eat more fresh foods. Take only supplements recommended by your doctor and pass on the rest. And stay on top of the news for latest updates on the topic.

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