Experts are now weighing in and warning about supplements in general.
There are mixed findings when it comes to taking fish oil supplements. British researchers found people with no heart history who regularly took Omega-3 fatty acids had a 13% increased risk of atrial fibrillation and a 5% greater stroke risk.
But the study also found that people with heart disease who took fish oil had a 15% lower risk of getting more severe heart problems.
Cardiologists say no trial to date has shown a significant heart benefit. Instead, doctors say to use food as medicine.
The same advice applies to many other supplements.
"What we really need are fruits and vegetables in that natural form. That's how your body can absorb the vitamins the best," said Internist Dr. Megan Mescher-Cox with Dignity Health St. John's Regional Medical Center.
She said our bodies can't absorb all the nutrients in supplements. But they are recommended for patients who have a vitamin deficiency.
"I do take a vitamin B for Vitamin B deficiency," said 61-year-old Leticia Garcia of Ventura.
Recently, she went vegan and doesn't consume any animal products. So her doctor recommends she takes B-12 supplements.
"If someone has a fully plant-based diet, we do recommend that they take a B-12 supplement once or twice a week," she said.
Mescher-Cox said various symptoms of vitamin toxicity include vomiting, body pain and an irregular heartbeat.
Experts say take a look at the tolerable upper intake level or UL. This is the daily maximum of vitamins and minerals that you can take without adverse health effects.
The UL can be found on product and government websites. But doctors warn the measurements may not be accurate.
"The actual active ingredient might change from one bottle to the other bottle," Mescher-Cox said.
Garcia no longer takes multivitamins.
"I was told it was kind of a waste of money because you do urinate most of it," she said.
"Save your money and don't buy all those supplements. Instead you can spend that money on the fruits and vegetables, said Mescher-Cox.
She recommends consuming a variety and aim for 9 to 11 servings per day.