Of the vitamins commonly used in modern medicine, vitamin K is known to play a big role in clotting of blood and in regulating calcium balance. This essential nutrient has two distinct forms – namely, vitamin k1 and vitamin k2. Vitamin k2 is also called menaquinone and it is sourced mainly from fermented foods as well as animal-based foods. On the other hand, vitamin k1 is mainly taken from plant-based foods – especially from leafy-greens. This variant of vitamin k is known to decrease calcium deposits on the walls of your blood vessels. As an added advantage, vitamin k2 also helps boost cardiac wellbeing and the health of your bones. However, vitamin k2 also triggers a few side effects; knowledge of its likely side effects is helpful before taking doses of this vitamin supplement.
Vitamins are essential for the overall wellbeing as well as growth of your body. Most vitamins are available through the foods you take. While vitamin k1 mainly focuses on clotting of blood, vitamin k2 supports a fairly wide spectrum of activities. Vitamin k2 is also stored up differently in your body. This form of vitamin gets accumulated in your kidney as well as brain. Vitamin k1 however is stored up in pancreas, liver and heart. Vitamin k2 is available in sizeable proportions in foods like eel, organ-based meats – such a liver of beef, egg yolk, chicken, etc. In general fermented foods are good sources of vitamin k2.
Vitamin k2 plays a greater role in maintaining cardiac being, mental health, protection from cancers, health of bones, etc. Vitamin k2 is also known for its ability to minimize repair of cardiovascular system, and thus helps promote wellbeing of your heart. A key protein strand – activated by this vitamin form – is known to keep away calcium deposits (calcification) on the walls of your blood vessels. Health of bones also benefits from a richer density of calcium; this is enabled by activating another protein which helps absorb calcium into bones. This vitamin form’s antioxidant properties can help fight cancers.
There is no daily recommended value for the intake of vitamin k2. However, 120 mcg (micrograms) of vitamin K is recommended for adult-males while 90 micrograms suit best for adult-women. You may need to note than more than 87% of vitamin K taken through foods belong to vitamin k1 category. The good news though is vitamin k2 is more easily absorbed by your body. Among children, a dose of 40 micrograms each day is considered as adequate; this level is however for children aged less than 13 years.
Side effects of vitamin k2
Intake of vitamin k2 may lead to a few side effects. Some of the minor discomforts of this form of vitamin include an altered sense of taste, flushing, discoloration or inflammation of the site of injection, etc. These may not require medical help or clinical treatment protocols. However, vitamin k2 may also result in a few other side effects that may be rare but are relatively serious in nature. Such serious side effects include erratic heartbeats, frequent spells of dizziness, formation of a bluish tint on skin, hypotension (decrease in blood pressure levels – this however is observed only as a short term effect), etc. In some people, it can also lead to excessive sweating.
Those who took vitamin k2 in its injectable form have experienced a few discomforts. Commonly experienced discomforts are respiratory problems, rashes on skin, itchiness, hives, erratic or rapid heartbeats, drowsiness, problems in swallowing, etc. Apart from these, an ingredient in vitamin k2 (called as phytonadione) can trigger adverse side effects among newly born babies. These include enlargement of liver, discoloration of eyes, crying persistently, being in an irritated frame of mind, respiratory problems, muscular problems such as stiffening of muscles, decrease in appetite, etc.
Vitamin k2 is not known to trigger a few allergic reactions. In extremely remote cases, intake of its supplements have caused some adverse reactions such as hives or rashes on skin, respiratory disorders such as wheezing or gasping for breath, inflammation of oral parts or facial organs, itchiness, etc. Vitamin k2 is also known to cause adverse side effects if taken with blood thinning medications such as warfarin. Blood thinners are mainly drugs taken to inhibit vitamin K – i.e., clotting of blood. When vitamin k2 is consumed, it is likely to disturb the functioning of warfarin or such types of blood thinning medications like coumadin, etc. You need to tell your doctor if you are taking thinners of blood, especially prior to starting a medication plan involving the intake of supplements.
Vitamin k2 is also likely to interact with a few types of antibiotics as well as obesity medications (such as orlistat). You are hence advised to check with your pharmacist as well as your treating doctor about the intake of antibiotics; this is because of some antibiotics’ capability to kill bacteria that are responsible for the making of vitamin k2. But, where do these bacteria reside? Such bacteria are mainly seen in your gut, especially in the large-intestine. Some people who took cholesterol reducing medications (especially those which work on your biliary acids) such as colestipol, etc. have also reported a few adverse interactions and side effects. The underlying reason is – these drugs may make your body to seek more vitamin k2 because of the absorption of vitamins by your bile.
Also, those who take vitamin A (preformed genre – for example, retinol) for a longer timespan have reported bone repairs. This is mainly due to a competition that arises between vitamin k2 and vitamin A. Some clinical studies also indicate scope for a likely conflict between vitamin D3 and vitamin A. You will need to remember that both these vitamins (D3 and k2) are essential for the health of bones.
It is hence important to remember that vitamin D3 can trigger an additional need for vitamin k2. So, 40 micrograms of this vitamin is commonly considered as safe for every 1000 IU of D3 consumed. For the same reason, your treating physician may advise you to take D3 after a time gap of say 9 to 10 hours. In order to naturally achieve such long time intervals between doses, vitamin k2 may be taken during bedtime, long after a dose of D3. This is also a reason why dietitians commonly advise you to consume vitamin D3 with your morning meals so that vitamin k2 can be taken during with dinner.
Also, people living with high levels of blood sugar or those who are diabetic may need to be careful while taking vitamin k2. This is because of this vitamin’s ability to influence insulin-sensitivity levels, especially at significant dosages. However, even at smaller dosage forms of less than 25 micrograms each day, this vitamin is found to have enhanced insulin-sensitivity levels. Significantly larger doses – if consumed over a longer span of time – can lead to impairing your hormonal balance to a greater extent. You also need to note that a few drugs can minimize the absorption of vitamin k2; these drugs include a few types of statins, drugs like cholestyramine, etc.
Precautions to be taken for the safer intake of vitamin k2
People with a few prior medical conditions or clinical history will need to report about their conditions to their caregiving team. Those who are living with hepatic disorders such as cirrhosis of liver, hepatitis (inflammation), etc. as well as conditions such as fibrosis or bowel-related disorders are at an added risk. Also, those who are experiencing disorders associated with their gallbladder, persistent episodes of indigestion or diarrhea, etc. may be prone to more risks.
Women who are pregnant must take needful guidance from their treating doctor prior to taking vitamin k2. Also, those who have plans to become pregnant need to consult a qualified medical practitioner before starting their medication plan that involves taking vitamin k2. Similar precautions are needed for women who are nursing a baby.
It is quite likely that at times you may forget to take a dose of vitamin k2. In such instances, never take a dual-dose of this vitamin supplement. Your pharmacist will advise you to skip the dose you forgot to take. In some instances, people may forget to take a few doses continuously. In those cases, you are advised to talk to your pharmacist who will help reschedule your entire dosage plan.
Interactions with other medications
This vitamin may interact with a few other drugs – i.e., apart from those listed above. It is hence a good practice to make a list of all the drugs you are currently consuming. As you compile such a list, make sure to include over the counter (OTC) medications, prescription drugs as well as herbal supplements. Take needful care to also include commonly used drugs such as ibuprofen, naproxen or other non-steroidal anti-inflammatory drugs (NSAIDs), cough relieving or pain killing medications. Once you have shared this list to your medical team, never change or stop taking any of the drugs. If you need to stop or change the drugs in the list, tell your treating doctor about such changes.
Your physician may advise you to undergo a few diagnostic tests to understand the efficacy of vitamin k2. One such test is the time taken for your blood to clot. It is essential to perform this test on a routine basis. Based on the outcomes of such tests – which indicate how well your body is responding, your physician may adjust the strength of vitamin k2 doses.
In general, vitamin k2 is considered to be safe for consumption. But, some people may develop a few minor side effects like an altered sense of taste, discoloration or inflammation of the site of injection. Such discomforts may not require medical help or attention. Moreover, most of these minor discomforts may disappear on their own once your body gets familiar with the ingredients of this vitamin supplement. If these discomforts do not disappear on their own, you need to get in touch with your doctor.
Also, if you notice side effects such as swelling of facial or oral organs, respiratory problems or dizziness, you need to take medical help as quickly as possible. Those living in the US must call 911 immediately or get in touch with a poison control center on an emergency basis. If you are living in any of the provinces of Canada, you are advised to contact Health Canada or a poison control center located at the province you live.
You also need to remember that the side effects or allergic reactions listed above do not form an entire list. So, if you encounter newer signs or symptoms, you need to inform your treating doctor without any delay. Such unknown side effects may also need to be reported by contacting the emergency helpline numbers of food and drug administration (FDA).
You also need to take proper care while storing this vitamin to avoid possible side effects due to improper storage conditions. This vitamin needs to be stored in a closed drug-box at ambient temperatures. Ensure that the place where you store it is out of reach of pets as well as children. It is important to store this drug without being directly exposed to sunlight, heat or excessive levels of moisture. Always remember that it is not a good practice to keep it in your refrigerator, or in the freezer box.
Education: Master’s in Nursing (MSN) from Johns Hopkins University. Experience: 7 years writing for online health portals and nursing journals, specializing in patient education and chronic illness management.
