It would be hard to put a nutrition label on a strawberry — and not just because it’s small.

Certainly the bright red juicy staple of summer has been poked and prodded. In fact, much is known about what makes this such a nutrient powerhouse in a small package: A single cup of strawberries can provide a person’s daily recommended allowance of vitamin C. And food science tells us that berries are a great source for antioxidants, which research shows may boost immunity and help build and repair tissues in the body.

The reason a strawberry — and other whole foods of all shapes and sizes — isn’t as simple to label as, say, a box of cereal is because of its sheer complexity. For every essential nutrient, like vitamin C, there are many other nonessential nutrients, like phytochemicals including antioxidants, not to mention the texture and structure of the food that experts say often helps the body get the most out of the food. That’s true even though cooking and some minimal processing can also be beneficial to help the body access certain nutrients like lycopene in a tomato.

“In all fruits and vegetables, you’re going to get a lot of fiber,” says Alicia Romano, a registered dietitian at the Frances Stern Nutrition Center at Tufts Medical Center in Boston. That fibrousness tends to be smoothed out and lost when fruits are processed or turned into juice (save for some pulp, like in orange juice). And while vitamin C is easy enough to deliver through fortification, what remains poorly understood is the longer term health benefits of countless nutrients in whole foods that aren’t typically added through fortification of foods. “The impact of these nonessential nutrients over the very long run — so we’re talking years or even decades — is not fully known,” says Job Ubbink, head of the Food Science and Nutrition Department at California Polytechnic State University in San Luis Obispo, California.

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But what’s clear is that there are fringe benefits from consuming food in its natural form that may be edged out or obscured when it’s simply broken down to component essential vitamins and nutrients. “By eating the whole food, essentially all of the nutrients come packaged already in balance with the other nutrients,” says Melissa Wdowik, director of the Kendall Reagan Nutrition Center at Colorado State University. “The body regulates the absorption, and so if you have vitamins or you have minerals or you have amino acids competing with each other, they do so at a really consistent rate with what the body needs — the body knows what to absorb and how much.”

If you get nutrients through fortification, in which vitamins and minerals are added to foods, these are often still well absorbed, sometimes even more readily than in their natural form. But the body doesn’t regulate absorption in the same way it does with whole foods, Wdowik says. And, she notes, the form of the vitamin or mineral is often different from how it’s found in nature.

But that’s hardly to say that fortification hasn’t provided significant benefit for many worldwide, as in the U.S. — starting with iodine added to salt in the 1920s. That essentially wiped away an epidemic of goiter, enlargement of the thyroid gland, at the time; adequate intake of the nutrient that’s found mostly in soil and water in coastal areas is needed for thyroid hormone production. “One of the pros of fortification is that it’s addressed public health issues,” Wdowik says. “I think historically it has been a really good idea.”

Many nutrients, like B vitamins, lost in the milling process — when grains are made into flour and prepared for cereal, for example — must, by federal mandate, be added back to those products, through a process called enrichment.

One of those nutrients, folate — that’s added through enrichment or fortification in its synthetic form, folic acid or vitamin B9 — has helped prevent the development of neural tube defects in babies. The defects involving the brain, spine or spinal cord can lead to issues like spina bifida, in which the spinal column doesn’t close properly, usually resulting in nerve damage that can contribute to at least partial paralysis of the legs. The prime window for prevention is right before a woman becomes pregnant through about roughly the first month of pregnancy or so when the defect develops. “Oftentimes women don’t even know that they’re pregnant. So it’s not something that you could take care of with supplementation,” says Amanda Palmer, assistant professor of nutrition and international health at Johns Hopkins University in Baltimore. Though folic acid supplements are often recommended to women seeking to become pregnant, many don’t take them, and many pregnancies are unintended. “You really need kind of this passive strategy,” Palmer says, and though the issue only affects a subset of women, that’s where fortification comes in.

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Most experts say that ideally fortification should be used to fill in gaps that can’t be covered through diet alone. It may also be recommended to help address certain documented or diagnosed vitamin or mineral deficiencies. Consider vitamin D, which is added to milk as well as some other fortified foods from cereal to certain brands of yogurt. Important for healthy bones, clinicians say often we don’t get enough through diet alone, though it’s naturally available through soaking up sunshine (something that’s supposed to be done in moderation to prevent skin cancer), and certain food sources, including fatty fish like salmon.

“Whole foods should always take priority,” Romano says, from fruits and veggies to whole grains, beans and nuts. It’s from these type of foods and an overall healthy eating pattern that experts say we should derive the majority of our nutrition.

In addition, if you’re choosing a food product that’s fortified, independently evaluate whether it’s healthy on the whole. Though certainly not true of all fortified foods (think milk, for example), Romano notes that many fortified foods have been highly processed, such as into a cereal or cracker form, with added sugar and salt. “I think that’s where some of the fortified foods can get a bad rap,” she says — when the fortified nutrients, or fortificants, are “added into foods that are highly processed and really not nutritious to begin with.” In that way, fortification can be leveraged as a marketing tool to provide a sort of health halo for some products that are anything but nutritious. These nutrients may be listed in a prominent way that seems to indicate the products are healthy, even if not explicitly stated as such, Ubbink says — and even if, in fact, it’s a cereal that contains as much sugar as a candy bar.

What’s also not known in a land where it’s normal to embrace supersized meals to the detriment of waist circumference is the additional impact getting too much of certain vitamins and minerals through fortification could have on a person’s health. More research is needed to determine that, Wdowik says.

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While other experts recommend using fortification to fill in gaps in a person’s diet, she advises that if people need to supplement their diet to get needed nutrients to do so with a multivitamin/multimineral supplement that’s taken once daily which provides 100 percent of recommended daily allowance of vitamins and minerals. “The reason is, Americans overeat everything — our portions are way too big.” Though studies show we absorb less than the full amount of vitamins and minerals when taken in supplement form, she says by taking one it’s easier to track how much one is getting, and a person could focus on eating smaller portions (rather than trying to eat more, in an effort to get nutrients through fortification). “Even if your body only absorbs 75 percent of [the nutrients in the supplement], at least you’re getting some, and you’re not getting too much,” she says.

Whatever role fortification might play in your diet — and no doubt it’d be hard not to eat fortified foods, given how common it is to add nutrients to foods — experts agree that whole foods should feature prominently in any healthy eating pattern. And dietitians say it’s critical to read the whole label — that is, when your food is labeled — while paying close attention not only what you eat, but how much.

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How Does Getting Nutrients From Fortification Compare to Whole Food? originally appeared on usnews.com