CEDAR FALLS - Many of today's adults were Flintstones kids.

They swallowed the chalky, chewable multivitamins shaped like Barney Rubble or Bam-Bam diligently without a second thought. Their parents knew they were getting all of their nutrients, no problem.

But they don't make adult Flintstones vitamins. Instead, the supplement industry pumps out hundreds of thousands of vitamins, both multisupplement and single-supplement, each with varying daily percentages and claims.

Unregulated by the U.S. Food and Drug Administration, vitamin manufacturers are numerous and it can be hard to differentiate Centrum from One A Day. It's not as simple as Flintstones anymore, but with a little help, you can figure out what supplements are right for you.

That is, if any are right for you at all.

"We always say we use the first line of defense - food," said Terrie Boring, a dietitian with Covenant Medical Center. "Food is naturally absorbed."

People who eat a diet rich in fruits and vegetables, and without a lot of starch, can usually get by without taking a multivitamin, Boring said. That's because those foods - compatible with the government's Food Pyramid - have all the nutrients your body needs.

But let's face it, not all of us can say we live a starch-free life or eat an apple a day. In that case, a daily multivitamin might be a good idea, said Mike Moreland, owner of Strive Sports Supplements in Cedar Falls. It means you'll be getting at least a percentage of your daily requirements of anywhere from five to 20 nutrients.

"It's much more cost-effective to take a multivitamin," Moreland said.

But there's a catch: You can't just pack 100 percent of every nutrient your body needs into one capsule and be done with it. What happens, say dietary experts, is your body will take only what it needs at that specific time and get rid of the rest.

So while you may be excited the label says you're getting 100 percent of your daily calcium needs, your body may only be taking 10 or 20 percent. You'll either have to make up the difference through repeated supplements at different times of day, or through the foods you eat.

Most vitamins can be supplemented through diet - for more vitamin C, have an orange. Others, like vitamin D, can be had with 30 minutes of sunshine.

Some vitamins aren't so easily made up, like iron.

"If you're anemic - iron deficient - that's pretty popular for women" to get, Moreland said.

Boring, however, recommends a non-iron multivitamin for those without anemia, because too much iron is toxic and can inhibit the absorption of other nutrients. Iron also can block nutrients like calcium.

If you suspect you're missing key nutrients, check with your doctor, who can recommend whether - and which - supplements are right for you. On the other hand, if you're just looking to supplement an already healthy lifestyle, check out the variety of multivitamins.

"Go with a well-known brand - (manufacturers) may have tested them better," Boring said. "No supplement is covered by the FDA, so it's good to have a good brand."

Contact Amie Steffen at (319) 291-1464 or amie.steffen@wcfcourier.com.