We eat food mainly for the macronutrients it contains, but we need micronutrients too. Macronutrients are the components of food that supply energy. They include carbohydrates, fat, and protein. Of these, carbohydrates and fat are most important as a source of energy. Your body normally doesn’t use protein as a major energy source, unless you’re in a starvation state or running a marathon. As long as there are enough carbohydrates available, protein is a minor energy source.
Micronutrients are components in food that your body needs in smaller amounts. They don’t supply energy, but, instead, act as cofactors, or helpers, in chemical reactions. However, you still need them to sustain life. The main types of micronutrients are vitamins and minerals.
Unfortunately, most people eat a diet high in energy, from macronutrients, and low in micronutrients. To make up for this shortfall, vitamin and mineral supplements have become popular. In fact, up to half of all Americans take some type of supplement that supplies vitamins and minerals. But, are supplemental vitamins really a substitute for the vitamins and minerals you get from food?
Vitamin Supplements versus Food Sources of Micronutrients
Most vitamin and mineral supplements contain micronutrients in synthetic form. They’re produced industrially and are in an isolated state. Yet there are some natural sources of isolated vitamins and minerals. Some of the more expensive supplements are made from whole food sources by removing the water. These supplements typically say so on the label. Although people are mistrustful of things made in a laboratory or produced industrially, your body can absorb vitamins and minerals in synthetic form as easily as natural ones. One exception is the most common form of vitamin E, alpha-tocopherol. You absorb this vitamin E isomer best in its natural state from food sources.
Is Absorption an Issue?
A vitamin or mineral has no benefits if you can’t absorb it. With a synthetic supplement, you take a pill and the outer coating of the pill has to dissolve and release the ingredient inside. Then, the active components have to be in a form your digestive tract can take up. How much is available to your body depends upon what else you have in your stomach, the medications you’re taking, your age, and the health of your digestive tract. You can get some reassurance by buying supplements with a USP symbol on the label. This means the supplements was independently tested and found to dissolve in the stomach.
It might seem that if you eat whole foods for micronutrients, absorption of the vitamins and minerals will be better. But that’s not always the case. Some fruits, vegetables, nuts, and seeds, and other micronutrient-rich, plant-based foods contain anti-nutrients, like phytates, oxalates, and tannins that interfere with the absorption of minerals.
Also, you can’t easily absorb fat-soluble vitamins from foods unless you consume them with fat. Examples of vitamins that you absorb better with a meal that contains fat include beta-carotene (a vitamin A precursor), vitamin D, vitamin E, and vitamin K. The same applies to fat-soluble vitamin supplements. A study published in the Journal of the Academy of Nutrition and Dietetics showed that guys who took vitamin D with a fatty meal absorbed 32% more vitamin D.
You Miss Out on Certain Things
Supplements might sound like a fast and easy way to get a dose of vitamins, but what are you missing out on? Fruits and vegetables are vitamin and mineral rich, but they are also a rich source of phytonutrients that have benefits that extend beyond simple nutrition. Many of these foods have anti-inflammatory and antioxidant benefits. In fact, plant foods contain over 25,000 phytonutrients. When you buy an isolated vitamin or mineral supplement, you don’t get these components or the synergy they offer. If you want the whole package, food is the best way to get your vitamins and minerals.
When Supplements Can Be Beneficial
There are situations where supplements have an advantage. If you have a documented vitamin or mineral deficiency, getting the missing component from food may not be enough, especially if you’re consuming foods that contain anti-nutrients that interfere with absorption. If you’re severely deficient in a vitamin or mineral, your health care provider won’t tell you to go home and eat more foods that contain that micronutrient you’re lacking, they’ll prescribe a supplement.
Another example where food isn’t enough is vitamin B12 deficiency. Deficiency of this vitamin, that’s critical for red blood cell production and a healthy nervous system, becomes more common with age. Usually, a deficiency comes from an inability to absorb vitamin B12 rather than a lack of dietary vitamin B12. If you have absorption issue, vitamin B12-rich foods may not be enough as you can’t absorb enough of it. Even vitamin B12 pills may be insufficient. In a case like this, a sub-lingual supplement you put under your tongue and that’s absorbed directly into the bloodstream is a safer bet.
Plus, at certain times in life, health care professionals recommend taking certain supplements. These include pregnancy where you need a folate supplement. You may also need an iron supplement and omega-3s in supplement form when you’re pregnant.
If you take a supplement, know that certain ones can interfere with other supplements and with prescription medications. Always let your physician know about all supplements you’re taking and the amount. Also, be aware that the Food and Drug Administration doesn’t test or review supplements before they enter the market. They only intervene if they get reports of adverse reactions. So, you don’t always know what you’re getting.
The Bottom Line
Synthetic vitamins and minerals. with the exception of vitamin E, may be absorbed as readily as vitamins in food. However, you miss out on the other components in vitamin and mineral-rich foods, such as phytonutrients. Plus, independent studies show supplements don’t always contain what’s on the label and may have more or less than what the label says. That’s why it’s best not to use vitamins and mineral supplements as a substitute for eating a whole food diet.
Journal of the Academy of Nutrition and Dietetics. February 2015Volume 115, Issue 2, Pages 225–230.
Harvard Health Publications. “Dietary supplements: Do they help or hurt?”
Am J Clin Nutr. 1998 Apr;67(4):669-84.
University Health News. “Which Foods Contain the Most Phytonutrients?”
U.S. Food and Drug Administration. “Dietary Supplements: What You Need to Know”