You know the drill: You have a ton of vitamins to take in a day but you’re not sure exactly when (or really if) you should take them all. And, while we should always turn to food for our vitamin and mineral intake, sometimes vitamin supplementation can help us fill the gaps in our diet. So here you are with your chosen vitamins (which should be properly prescribed and/or recommended by a medical professional) and you don’t know what’s the best strategy to take them.
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Part of the reason behind the confusion is for some supplements, your absorption level can depend on which ones you are taking together and may also result in adverse interactions, which can be harmful to your health.
Here are six vitamin combinations you definitely shouldn’t take together.
Many people like to take magnesium in the evening, as it can promote a sense of calm and supports muscle relaxation. But if you do take magnesium, Erin Stokes, ND, recommends not taking it at the same time as your multivitamin, as it may interfere with the absorption of smaller minerals found in the multivitamin, like iron and zinc. Additionally, she says to refrain from taking calcium, magnesium or zinc together as they will “compete for absorption.”
While Dr. Jaydeep Tripathy says taking calcium and magnesium helps prevent osteoporosis, in order to maximize the benefits, take them two hours apart.
“Studies have shown that a person’s absorption of Vitamin K may be reduced when other fat-soluble vitamins such as Vitamin E and Vitamin D are taken together,” says Dr. Chris Airey, M.D. “It’s advised that you take these vitamins at least 2 hours apart to maximize your absorption.”
Thankfully, there are no harmful side effects, however Dr. Airey says it’s “simply not efficient” to take them together as your body’s ability to absorb the vitamins will be reduced if you take them together.
While omega-3 fish oil supplements are great for heart health and gingko biloba can be used to aid cognitive impairment, according to Dr. Tripathy, both have blood-thinning potentials and “taking both together can increase risk for uncontrollable bleeding or inability to clot.”
If you are taking copper supplements because of copper deficiency, avoid taking zinc at the same time, says Dr. Airey. “Zinc can help to boost the immune system but can interfere with your body’s absorption of copper. If you must take both, take them at least two hours apart.”
Signs that you are still dealing with copper deficiency include fatigue, weakness, brittle bones, cold sensitivity and easy bruising.
While green tea isn’t a supplement, it is a delicious antioxidant-infused beverage that many of us enjoy for its health benefits. Unfortunately, taking iron supplements along with green tea isn’t a great mix.
“Green tea can actually cause iron deficiency if taken in large quantities for longer periods of time,” says Dr. Tripathy. “Iron, on the other hand, can decrease the efficacy of green tea.”
The solution? Skip green tea on days when you’re taking your iron supplement and decrease your weekly consumption.
According to Dr. Airey, some studies have shown that Vitamin C could break down Vitamin B12 in your digestive tract, reducing your B12 absorption. As a result, he says you want to wait at least two hours before taking Vitamin C with your Vitamin B12.
“Vitamin B12 plays an important role in red blood cell production and the proper functioning of your nervous system, and B12 deficiency can lead to poorer nerve health and affect red blood cell development and function.”
While the mixing of supplements can be overwhelming at first, Stokes says the most important aspect of a supplement regimen is to keep it simple, to set yourself up for success. “For example, I always take my multivitamin and turmeric supplements in the morning, and take my magnesium and probiotic in the evening. That’s the basic schedule. Depending on the season, I may add in extra zinc and vitamin D3, which I take with lunch. Once you get into a routine, and know what to take when, it just becomes part of your daily habits. It doesn’t have to be complicated.”
A version of this story was published March 2021.
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