General Questions about Vitamin K2 and Vitamin D3
What is vitamin K2? What is vitamin D3?
Vitamin D is a fat-soluble vitamin that has many documented functions in the human body including supporting calcium absorption, bone, dental, immune, breast and prostate health. Vitamin D2 (ergocalciferol) is a form of Vitamin D found in some plants, mushrooms, and yeast. Vitamin D3 (cholecalciferol) is the form made within human skin upon exposure to UVB radiation from the sun. Vitamin D3 can also be found in dietary supplements produced from lanolin or lichen. Evidence suggests that vitamin D3 may be more effective than D2 in maintaining stable levels in the human body.
The name vitamin K refers to a family of fat-soluble vitamins that possess a similar chemical structure but differ by the length of their side chains. Vitamin K1 (phylloquinone) is found in green leafy vegetables and is the primary source of vitamin K in the American diet. Vitamin K2 (menaquinone) is of microbial origin and is mainly present in select fermented foods like natto (fermented soybeans). While there are multiple forms of vitamin K2, the most bioavailable and biologically active form is MK-7, naturally present in natto. Vitamin K supports calcium absorption, and heart, bone dental, and prostate health.
What are some risk factors for a vitamin K and/or vitamin D deficiency?
Individuals who have a difficult time digesting or absorbing fats are at a greater risk of deficiency since vitamin K is a fat-soluble nutrient. This includes those with gastrointestinal malabsorption disorders, impaired liver function and those with cystic fibrosis. The long-term use of some antibiotics may also negatively impact vitamin K synthesis and absorption. Anticoagulant medications, such as Warfarin, often function as vitamin K antagonists and may impact vitamin K levels and/or vitamin K-dependent clotting factors. If taking medication, especially anticoagulant medications, it is very important to consult with a healthcare provider before consuming vitamin K from food or supplementation.
Vitamin D is a common nutrient deficiency in the United States. Groups that are at high risk for developing vitamin D deficiency include:
- individuals who primarily work indoors with limited sun exposure;
- individuals with dark skin because their skin has less ability to produce vitamin D from the sun;
- obese individuals because their body fat binds to vitamin D, which prevents it from getting into the blood; and
- older adults because their skin doesn't make vitamin D when exposed to sunlight as efficiently as it does in younger individuals.
It may be important to note that those who live in northern climates, where the intensity of UVB radiation tends to be less, often make insufficient amounts of Vitamin D and people with gastrointestinal disorders or malabsorption syndromes may also be at an increased risk for deficiency.
Are there any food sources of vitamin K or vitamin D?
Most western diets today provide vitamin K1 (phylloquinone) but very little vitamin K2 (menaquinones). Vitamin K1 can be found in leafy green vegetables and some plant oils. Vitamin K2, however, is of microbial origin and is typically found only in select fermented foods such as some types of cheese (not processed), curds, and natto. The most reliable food source of Vitamin K2 is natto, a type of fermented soybeans. Natto provides vitamin K2 as MK-7, the most bioavailable and biologically active form of vitamin K2. Given that most diets provide little to no vitamin K2, supplementation may sometimes be necessary to meet the recommended dietary allowance.
One of the main sources of vitamin D comes from sunlight as it stimulates vitamin D synthesis in the skin. There are a few reliable food sources of vitamin D as well including salmon, tuna, sardines, and eggs. Some foods are fortified with vitamin D such as milk, cereal and juices. However, these fortified foods may sometimes contain the less bioavailable Vitamin D2 (ergocalciferol) form.
How does vitamin K1 differ from vitamin K2 in regard to function and benefits?
The main role of vitamin K1 is supporting normal blood coagulation, or clotting. Vitamin K1 is primarily active in the liver with only a small amount being released for circulation in the body. Vitamin K2, on the other hand, especially the long-chain form MK-7, is circulated throughout the body and activates multiple vitamin K dependent proteins. This is one reason why vitamin K2 may provide unique and separate benefits from vitamin K1. Research demonstrates that vitamin K2 helps the body absorb and utilize calcium efficiently, directing calcium to bones and away from arteries, supporting both bone and cardiovascular health in the process.
What’s the difference between Vitamin D2 and Vitamin D3?
Vitamin D2 (ergocalciferol) is a form of vitamin D found in some plants, mushrooms, and yeast. Vitamin D3 (cholecalciferol) is the form made by the body when the skin is exposed to UVB radiation from the sun. Vitamin D3 can also be found in dietary supplements produced from lanolin or lichen. Evidence suggests that vitamin D3 may be more effective than D2 in maintaining stable vitamin D levels in the human body.
Is it necessary to take vitamin K with vitamin D?
Vitamin D and vitamin K2 work synergistically to support proper calcium absorption in the body. While vitamin D promotes the absorption of dietary calcium and helps maintain blood calcium levels, vitamin K2 helps activate specific proteins that direct calcium to bones and teeth. Vitamin D and vitamin K2 work together to support both bone and cardiovascular health.
Some customers prefer the convenience of getting both vitamins in one product. If interested, we make a combination product called K2 + D3 Gold. However, as a matter of principle and in the interest of your health and safety, we encourage you to consult your healthcare provider prior to supplementation to determine what use, if any, is best for your individual needs.
What is the recommended dietary allowance for vitamin K and vitamin D?
The 100% daily value (%DV) for vitamin K for individuals 18 years of age and older is 120 mcg. This goes down to 90 mcg per day during pregnancy/breastfeeding. As with any supplement, please talk to your healthcare provider prior to supplementation to ensure you are following the dosing schedule that is right for your particular health needs.
The 100% daily value (%DV) for vitamin D for individuals 18 years of age and older is 20 mcg (800 IU). This goes down to 15 mcg (600 IU) per day during pregnancy/breastfeeding. As with any supplement, please talk to your healthcare provider prior to supplementation to ensure you are following the dosing schedule that is right for your particular health needs.
Is there an established upper toxicity limit for vitamin K or vitamin D?
The Upper Tolerable Limit (UL), established by the Food and Nutrition Bard (FNB) of the Institute of Medicine, is considered to be the highest amount you can take of a nutrient without theoretical risk. The UL established for Vitamin D in adults is 100 micrograms (4,000 IU) per day. However, it is common for a medical provider to determine that a larger amount of Vitamin D is necessary in cases of severe deficiency.
The Upper Tolerable Limit (UL), established by the Food and Nutrition Bard (FNB) of the Institute of Medicine, is considered to be the highest amount you can take of a nutrient without theoretical risk. Vitamin K has a very low level of toxicity in the human body since it is rapidly metabolized and is stored only in small amounts. Given this, the FNB has not established an upper intake level (UL) for vitamin K. This applies to both vitamin K1 (phylloquinone) and vitamin K2 (menaquinone).
Can vitamin K2 and D3 supplements be taken with OTC or prescription medications?
If you are taking or planning to take an OTC or prescription medication, please consult a licensed pharmacist or your healthcare provider before beginning supplementation to minimize risk of side effects associated with potential supplement-drug interactions. Vitamin K may interfere with oral anticoagulants or blood thinning medications and should always be discussed with a licensed health provider before consuming.
Questions about Vitamin K2 + D3 Gold
What are the sources of K2 and D3 in Vitamin K2 + D3 Gold?
The vitamin K2 in our Vitamin K2 Gold product is sourced from natto, a traditional Japanese food made from fermented soybeans. We have chosen this natto source of vitamin K2 for two key reasons—Vitamin K2 (as MK-7) is naturally present in high amounts in natto and the MK-7 form of K2 is the most bioavailable and biologically active form of vitamin K and helps ensure consistent blood levels of this vitamin.
All of our Vitamin D3 Gold products, including Vitamin K2 + D3 Gold, feature vitamin D from wild-crafted, sustainable lichen—a food source of natural Vitamin D3. Lichen is an organic-compliant, vegan, kosher, allergen-free non-GMO verified source of bioavailable D3.
Is lichen-sourced vitamin D3 safe for human consumption?
Yes, lichen has been historically consumed in Europe, Asia and America as human food. The vitamin D3 in our product is sourced from Reindeer Lichen, a species of lichen traditionally used by Native Americans as food. Our wild-crafted lichen is not treated with any pesticides, collected using an environmentally-friendly and sustainable method, and gently extracted using food-grade ethanol only. In addition, lichen is an organic-compliant, vegan, kosher, allergen-free non-GMO verified source of bioavailable D3, which is consistent with our commitment to making the cleanest supplements using the purest and most sustainable ingredients available.
Which source of Vitamin D is more bioavailable—lichen or lanolin?
There should be no difference in bioavailability between vitamin D from lichen and vitamin D from lanolin. Both sources provide vitamin D as cholecalciferol, the form made in skin upon exposure to sunlight.
How does NutriGold ensure the purity of the ingredients used in its K2+D3 Gold product?
At NutriGold, we go above and beyond what is recommended or required under current GMPs to independently verify that the raw materials used in our products as well as the finished products themselves meet industry-defining quality and purity standards. Depending on the complexity of the testing involved, including determining what needs to be tested, what methods are fit-for-purpose, and which lab is most qualified to perform the testing, we sometimes have results from as many as 4 or 5 different independent, ISO-certified labs for each product. We take these results from third-party labs and summarize them in lot-specific Certificates of Analysis that are freely available in the spirit of authentic transparency on the product pages on our website so consumers can make informed purchasing decisions.
What assurance can you provide that the amount of K2 and D3 listed on the label is actually in the product?
All of our products are verified by independent third-party labs to meet identity, purity, and potency label claims. We take these results from third-party labs and summarize them in lot-specific Certificates of Analysis (C of A) that are freely available in the spirit of authentic transparency on the product pages on our website so consumers can make informed purchasing decisions. The C of A provides assurance that the claims made on the label accurately reflect the contents of the product inside the bottle. If interested, more information on our our commitment to independent, third party quality testing can be found at this link - https://nutrigold.com/pages/accountability
What is the best time of day to take Vitamin K2 + D3 Gold? Should it be taken with food?
Vitamin K2 and vitamin D3 are fat-soluble vitamins. Most fat-soluble vitamins (e.g. A, E, K) are better absorbed when consumed with dietary fat (usually a component of most meals). However, as a matter of principle and in the interest of your health and safety, we encourage you to consult your healthcare provider prior to supplementation to determine what use, if any, is best for your individual needs.
Why does K2+D3 Gold contain tapioca maltodextrin?
At NutriGold, we are philosophically opposed to the use of chemical additives and synthetic preservatives in our products. For this reason we avoid magnesium stearate and silicon dioxide as well as additives commonly sourced from GM ingredients like corn starch, corn maltodextrin, and soy lecithin. Although we make every effort to manufacture products without the use of any excipients, there are situations when an additive may be required to ensure production efficiency and finished product integrity. When that happens, we take care to use plant-based additives like the tapioca maltodextrin in our K2+D3 Gold product.
Can I break apart the capsule and add the contents to liquid/food to consume?
All of our products are formulated to be taken as capsules and our purity and potency claims are based on the product being taken as recommended. We generally do not recommend breaking apart the capsules because it can introduce contaminants or otherwise compromise product potency and effectiveness.
Is K2+D3 Gold suitable for children (under 18 years of age)?
K2+D3 Gold is formulated for individuals over 18 years. Because children are considered a vulnerable population, we regret we cannot make any recommendations regarding the use of our products by or for children under the age of 18. We ask that you talk to your pediatrician or family practitioner about whether or not Vitamin D3 Gold is suitable and safe for your child’s particular healthcare needs prior to supplementation.