C-ing is B-elieving — supplements are everywhere these days.
Over 100,000 dietary or nutritional supplements are sold in the US alone. One survey indicated that about 74% of American adults take these products for health, energy or disease prevention, with 55% considered regular users.
Unfortunately, many people misuse supplements because they’re unsure how much to consume, when to take them or whether they interact with their medications.
Improper supplementation can cause more harm than good, potentially leading to nutrient toxicity, damage to the liver, kidneys or heart, nerve damage, gastrointestinal distress and increased cancer risk (like when smokers take beta-carotene).
Don’t worry, it’s going to be A-OK. Dr. Pooja Gidwani, a double board-certified internal and obesity medicine physician based in LA, shares the ABCDs of how — and when — to take common supplements.
Fat-soluble vitamins (A, D, E and K)
These vitamins — some of the most popular and essential for vision, immune support, bone health and blood clotting — dissolve in fat and are stored in the liver and fatty tissues.
That’s why it’s important to take them with a meal, especially one that contains some dietary fat.
“These vitamins rely on fat for absorption in the gastrointestinal tract, and taking them on an empty stomach can significantly reduce how much is absorbed,” Gidwani said. “Even a modest amount of fat is sufficient, but consistency matters.”
She noted that timing is less important, though vitamin D is recommended for mornings since it can provide energy.
Water-soluble vitamins (C and B-complex)
Unlike fat-soluble vitamins that get stored in the body, excess amounts of water-soluble vitamins are flushed out via urine.
They require regular intake but don’t need to be consumed with food.
“However, taking them with food may reduce stomach discomfort, which is more common with higher doses or B-complex formulations,” Gidwani said.
“These vitamins are generally best taken earlier in the day, as B vitamins can feel stimulating for some individuals.”
Iron
Iron is key for making hemoglobin, which carries oxygen from your lungs to the rest of your body, to combat anemia symptoms like fatigue, weakness and shortness of breath.
“Iron is best absorbed when taken on an empty stomach, as food can significantly interfere with absorption,” Gidwani said.
“It is often recommended to take iron with vitamin C or a vitamin C–rich beverage to enhance uptake.”
Gidwani reported that iron should be kept separate from calcium, dairy products, coffee, tea and multivitamins, which can reduce absorption.
If you experience nausea, abdominal discomfort or other gastrointestinal issues, she recommends taking iron with a bit of food.
“This may slightly decrease absorption but can improve tolerability and long-term compliance,” Gidwani explained.
Omega-3 fatty acids
Fish, krill and algal oils are designed to support heart, brain and eye health because they are rich in EPA and DHA omega-3s.
Gidwani said these supplements should be taken with meals containing healthy fats, and the time of day doesn’t matter as much as consistency.
“Some people prefer to take it at night if it causes belches, and some like to split it (take half of the dose in the a.m., and half of the dose in the p.m.) if it causes digestive issues,” she shared.
Probiotics
These beneficial bacteria and yeasts balance the gut microbiome, support digestion, reduce inflammation and boost nutrient absorption.
“Probiotics are generally best taken with food or just before a meal,” Gidwani said.
“Food helps buffer stomach acid, improving the survival of probiotic organisms as they pass through the stomach and into the intestines.”
Gidwani suggests taking probiotics at the same time every day. If you also consume antibiotics, be sure to take probiotics at a different time to avoid reducing their effectiveness.
Multivitamins
Multivitamins are the most popular supplement in the US, and it’s important to check the label to make sure you know what you’re consuming.
“Most multivitamins contain a mix of fat-soluble vitamins, water-soluble vitamins and minerals, making food particularly important for tolerability and bioavailability,” Gidwani said.
“They are typically best taken earlier in the day, since B vitamins can feel energizing for some people.”
She advises against taking a multivitamin at the same time as an iron pill because it can interfere with iron absorption.
No matter what supplement you take, it’s important to check with a healthcare provider who can provide guidance on potential benefits, risks, appropriate doses and necessary precautions.
