Q: Is wine high in vitamin K?—Spence, Fort Wayne, Ind.
A: Our last Health Q&A took a close look at wine and vitamin D. Vitamin K, specifically the K2 form, is often combined with vitamin D3 in oral supplements, which have recently seen a spike of attention on social media and the web. The thinking goes that since the body needs both vitamins to process calcium, the combination may provide special benefits. Does wine contain any of this essential vitamin?
What Is Vitamin K?
Vitamin K is a group of fat-soluble compounds that are crucial for blood clotting. The molecules also help the body use calcium and can impact bone health.
Vitamin K comes in two forms. K1, or phylloquinone, is found in plants, where it’s used in photosynthesis. It’s found in highest amounts in green leafy vegetables, but many fruits and veggies, including grapes, contain K1.
Vitamin K2, or menaquinone, is found in animals and some fermented foods. Eggs and poultry are especially good sources. The human body can use both forms of the vitamin, which is absorbed in the small intestine, and gut bacteria also produce vitamin K.
Vitamin K in Wine
According to the United States Department of Agriculture, both red and white wine contain a very small amount of vitamin K1—just 0.4 micrograms. In the United States, the recommended adequate intake level of vitamin K is 120 micrograms per day for adult men and 90 micrograms per day for adult women. So while wine contains more vitamin K than it does vitamin D, don’t count on a glass or two to make a meaningful contribution to your daily intake.
The good news is that you’re almost certainly getting enough vitamin K from your diet. While insufficiency of other nutrients, including vitamin D, is fairly common, most adults get enough vitamin K, and supplementation isn’t necessary for most people.
If you’re taking certain antibiotics or blood thinners, particularly Warfarin (or coumadin), you may need to watch your vitamin K consumption. People with liver disease, which can result from chronic heavy drinking, sometimes have vitamin K deficiency. If you’re concerned about your vitamin K levels, you should consult a doctor.
As always, talk to your healthcare provider about incorporating wine into a healthy lifestyle.—Kenny Martin
