The IP address used for your Internet connection is part of a subnet that has been blocked from access to PubMed Central. Addresses across the entire subnet were used to download content in bulk, in violation of the terms of the PMC Copyright Notice. Use of PMC is free, but must comply with the terms of the Copyright Notice on the PMC site. For additional information, or to request that your IP address be unblocked, For requests to be unblocked, you must include all of the information in the box above in your message.If you are a heart patient who is taking blood thinners, such as warfarin (Coumadin®), you need to be careful not to overdo vitamin K. Blood thinners are often prescribed for people at risk for developing harmful blood clots. If you suddenly increase your intake of vitamin K intake in your diet, it can have an unintended consequence. It can actually decrease the effect of warfarin. This is because vitamin K is an essential part of the chemical process for forming blood clots in your body.
You don’t want to cut out vitamin K completely, as it is present in a variety of healthy, nutrient-rich foods. These include leafy greens and many vegetables. Instead, be smart about how much vitamin K you consume, be consistent, and work with your doctor to find just the right balance. For example, if you eat a diet rich in vitamin K, you may need to check your blood a little more frequesntly or take more warfarin. If you change your diet and eat fewer foods containing vitamin K, you may need to take less warfarin. Work with your doctor to find the right dose for you. Here are three tips to help you safely manage your vitamin K intake: “Vitamin K foods can be included in your diet on a regular basis as long as you are mindful of the portion and keep the overall intake of vitamin K-rich foods consistent, says Julia Zumpano, RD, LD. For instance, you can choose to have a vitamin K rich food every day, every week, or three times in a week—as long as you keep this portion and frequency consistent, she says.
“If necessary, you can discuss including regular sources of vitamin K in your diet with your doctor in case your warfarin dosage would need to be adjusted,” she adds. You will want to tell your physician how often you eat foods high in vitamin K and how much of those foods you eat. Being knowledgeable about vitamin K is a key to managing it in your diet. There are a variety of vegetables that contain lower amounts of vitamin K. Iceberg lettuce is low and romaine is also fairly low, so most people can eat either if them daily. In addition, be sure to read labels on multivitamins as they have varying amounts of vitamin K. Talk to your doctor about what vitamins you should take. RELATED: Atrial Fibrillation Treatment Guide You may need to avoid certain supplements and vitamins to keep your blood values stable. Talk to your doctor about any and all supplements you take to be sure they are not interfering with your blood thinners. RELATED: Should You Take Aspirin If You Are on Blood Thinners?
Another way to manage how well your blood thinners work is to take your dose of warfarin at the same time each day, and from day to day, make sure your vitamin K intake is consistent. To be sure you’re on track, have your blood values checked regularly (usually once per month with your physician; this may be more often during dose adjusting). Below, find more details on the amount of vitamin K present in different foods, including leafy greens, vegetables and other foods as provided by the U.S. Department of Agriculture. When it comes to blood thinners, the more you know the better you can manage your diet. Be sure to talk to your doctor if you have any concerns.Vitamin C is a water-soluble substance, and therefore does not accumulate in the body. This accounts for the absence of any data on vitamin C toxicity per se. Vitamin C in itself is of low toxicity, and has only minor adverse effects, such as diarrhea, nausea and other digestive disturbances. These upsets are due to the osmotic withdrawal of water from the intestinal contents by the unabsorbed vitamin C in the gastrointestinal tract.
Other physiologic disruptions due to high vitamin C levels include metabolic acidosis and altered levels of some coagulation factors such as prothrombin. Vitamin C metabolism produces oxalate as a product. Some research suggests that vitamin C supplements may increase urinary oxalate concentrations, and double the risk of calcium oxalate kidney stones. Several drugs reduce vitamin C levels, such as the contraceptive pills that contain estrogen, barbiturates and tetracyclines. Vitamin C also raises estrogen levels. Regular aspirin intake above a certain frequency, such as 1000 mg every 6 hours, increases the urinary excretion of vitamin C and reduces its blood levels. Vitamin C causes higher serum levels of aspirin and other NSAIDs. Vitamin C can inhibit the action of warfarin, and thus the dosage of warfarin requires to be monitored by the prothrombin time. It may also reduce the cardioprotective action of cholesterol-lowering drugs such as simvastatin and niacin, though the evidence is far from clear.
Some large trials indicate that it does not affect the positive effects of these drugs. It has been suggested that vitamin C use during cancer cell chemotherapy could diminish the efficacy of treatment by protecting tumor cells from destruction. Other studies, though, indicate that vitamin C exerts a possible protective effect on normal cells against the damage induced by radiotherapy or chemotherapy. It has also been suggested that high doses of vitamin C could lead to oxidative damage by contributing to free radical production, but this has not been experimentally shown. Tests such as serum bilirubin, serum creatinine and the guaiac test for the presence of occult blood depend upon the presence of reducing substances, and thus high levels of vitamin C can interfere with their interpretation. A single study showed that vitamin C supplementation appeared to increase the cardiovascular disease mortality in post-menopausal diabetic women, but this has never been confirmed.