Adding vitamins and supplements to your wellness regimen can be one great way to prioritize your health, especially if you’re worried about fitting the right nutrients into your diet naturally. However, it’s always important to be mindful of the risks of anything you’re putting into your body—and as it turns out, many supplements come with potential downsides, especially when combined.
There are a lot of potentially harmful supplement combinations to be aware of as you look out for your health. According to experts, one such combo is vitamin E and vitamin K. Although both of these nutrients are integral to your overall health, combining them in high doses could interfere with your body’s natural blood clotting processes and even raise the risk of bleeding. We spoke to Janelle Bober, MS, RDN from Dietitian Live to learn more about the potential risks at hand. Read on for all of her expert insight on the matter.
Risks of combining vitamins E & K
It can be easy to get carried away with supplements and load your daily intake up with everything you think you need to help your body thrive—but beware of overkill. Taking vitamin E and vitamin K at the same time can do more harm than good, Bober says.
"Vitamin E and vitamin K are both fat-soluble vitamins, and two of the biggest things to understand is that vitamin E can interfere with blood clotting and vitamin K’s role in blood clotting," she says. "What happens is it basically takes over absorption, so it might interfere with the absorption, and it inhibits a specific enzyme activity that doesn't support our ability to form clots appropriately."
Evidence shows that high doses of vitamin E (over 1,000 IU per day) can reduce vitamin K’s effectiveness in helping the body form clots. "It’s mostly a risk in people who are at risk for blood clots or who have bleeding disorders or who are taking anticoagulants," she says. "Blood thinners or anticoagulants like warfarin or aspirin can increase your risk of this interaction." Older adults and people with vitamin K deficiencies—whether due to fat malabsorption, liver disease, or prolonged antibiotic use—are especially at risk of these effects.
In order to keep your health and safety in check, Bober recommends avoiding high-dose vitamin E supplements unless told otherwise by a healthcare professional. "The upper intake level for vitamin E is 1,000 mg per day or 1,500 international units," she explains. "Supplements may exceed this level, especially if it's recommended by a medical professional, but in any case, don't supplement vitamin E or vitamin K unless advised by a doctor."
Because these vitamins are fat-soluble, the body stores them in fat tissue rather than flushing them out like water-soluble vitamins, Bober further explains. This increases the likelihood of toxicity or other adverse effects if taken in excess. The solution? Get your nutrients from your food. "With most supplementations, I would recommend focusing on dietary intake instead of supplementation unless you medically need it," Bober says.
You can up your intake of vitamin E with foods like sunflower seeds, almonds, hazelnuts, avocados, and spinach. Meanwhile, vitamin K is found in dark leafy greens like kale and spinach, as well as broccoli, Brussels sprouts, egg yolks, and hard cheeses. "For both of these vitamins, it's really important to make sure that you're including a fat in your meal with them because that helps us to absorb more of them," Bober adds. All in all, "More isn't always better, especially with fat-soluble vitamins like vitamin A, vitamin D, vitamin E, and vitamin K."
In addition to a "food first" approach, she recommends reaching for a multivitamin in balanced doses—"Something that's safe and low-grade." Of course, always talk to a healthcare provider, too, as "They have a deep understanding of pharmacology and the interaction of medications." Got it!
