Taking a daily multivitamin or supplement may put you in a better position to be healthy, but if you’ve ever taken one and felt immediately ill, you know it’s never a fun experience — and it might even make you want to quit the habit altogether.
Taking certain types of vitamins can cause a variety of gastrointestinal issues, says gastroenterologist David Poppers, M.D., of NYU Langone Medical Center. It’s not uncommon to experience abdominal pain or discomfort, nausea, and diarrhea.
When it comes to vitamins and supplements, there are a number of factors that can cause stomach problems. Below are some of the reasons why vitamins and supplements can make you feel unwell:
I take my vitamins on an empty stomach.
Poppers told HuffPost that more acidic vitamins, like vitamin C and folic acid, can cause nausea if taken on an empty stomach.
“Taking your vitamins with a snack or a small amount of food can provide some buffering,” he said, adding that some nutrients are better absorbed when taken with food, but some supplements may be better taken on their own.
“Fat-soluble vitamins such as vitamins A, D, E and K are different from other vitamins in that they may be better absorbed when not taken with a meal,” Poppers said.
Your medication contains a lot of iron.
According to Donald Hensrud, M.D., medical director of the Mayo Clinic Healthy Living Program, iron-rich multivitamins (such as prenatal vitamins) and iron supplements themselves can cause nausea, especially if taken outside of meals.
“Iron is interesting in that it’s best absorbed on an empty stomach, but it’s hardest to take on an empty stomach because it makes you nauseous,” Hensrud says. “I tell people it’s better to take it with a meal than to try to take it on an empty stomach and feel ill and then decide not to take it at all. It might reduce absorption a little bit, but it’s better than nothing.”
I am taking vitamins along with other medications.
You might want to take a look at your medicine cabinet.
“Vitamins are like drugs in that they can interact with each other and with other medications you’re taking,” Hensrud says. “It’s really important to go over combinations with your doctor to make sure there aren’t any adverse interactions that could interfere with their effectiveness.”
Hensrud added that his findings suggest that multivitamins may cause side effects if taken when estrogen levels are elevated (potentially when combined with birth control pills). all Any medications you are taking – including any added nutrients.
You might be taking your vitamins at the wrong time.
“It’s important to consult with a health professional about the timing of taking these vitamins,” Poppers says. “While they may complement each other, one may be absorbed less well than the other.”
For example, iron is better absorbed when taken with vitamin C, Poppers explained. But taking iron with calcium can have the opposite effect.
The label on your vitamin supplement should have details on how to take it, including its ingredients, how it’s made, and the percentage of your daily value for that nutrient. Review the information before taking it to see what else you need to know.
Additionally, Poppers and Hensrud stress that it’s essential to always consult a doctor before starting a daily vitamin or supplement and to let your doctor know if you experience any side effects. You can usually get the recommended daily intake through a proper diet. Most people don’t need to take large amounts of a nutrient unless they have a deficiency, says Hensrud.
Poppers explained that a simple blood test can be performed by a doctor to determine what vitamin deficiencies you have and, based on the results, your doctor can recommend the best treatment.
“Like most things related to health, taking vitamins is very complicated,” Poppers says.
