Vitamin D3 is actually a fat-soluble form of Vitamin D that is naturally found in our bodies and triggered through our skins by sun exposure. There are also some foods that have vitamin D3 e.g seafood but it is also possible to take vitamin D3 from supplementation. It is mainly responsible for maintaining adequate calcium levels in the body and specifically in our blood bones and skin tissue.
Dietary recommendations suggest that adult males and females should take ideally around 600 IU (15mcg) of the Vitamin daily from diet or supplementation.
Vitamin K2 is a fat-soluble form of Vitamin K (also going by the name menaquinone) which is 90% stored in our livers. It plays an active role in help preventing blood clotting and help keep our bones, muscles, ligaments, skin, and nails in a healthy condition. The Vitamin is naturally found in certain foods like green leafy veggies, meat, cheese, eggs, oils and some fruits.
According to official guidelines3, adult males should take 120mcg of the Vitamin every day while females should ideally take 90mcg of Vitamin K per day.
Uses of Vitamins D & K- why do our bodies need them?
Bone and tissue health. The primary role of vitamin D and D3 as one of its forms, is to support bone and tissue health. This is achieved through various ways and specifically by enhancing absorption of calcium and phosphorus which are both vital for bone formation. It also helps prevent osteoporosis and osteomalacia (softening of bones) in sensitive groups like children and adults of age 55+4 especially when taken with calcium and Vitamin K. As matter of fact, osteoporosis (decrease in bone density), which a disease that bothers millions of people worldwide, is often caused by deficiency in Vitamin D and calcium.
Cancer. Several studies have examined the role of Vitamin D in helping reduce cancer risk or even prevent cancer from spreading spread. There are some studies that show that Vitamin D supplementation could be useful for preventing certain types of cancer like Endometrial and Breast cancer5,6 as its deficiency is linked with a higher risk of developing such cancers. Another impressive side effect of vitamin D when it comes to cancer, is its ability to lessen the pain of cancer symptoms in hospitalized patients, as found in a study conducted this year7.
Depression. The popular notion that our bodies produce vitamin D3 during sun exposure which makes us feel happier is actually not a myth. In fact, some studies8.9 have found that vitamin D/D3 can reduce the risk of depression in adults and control the severity of its symptoms. A 2004 study10 conducted on women who took vitamin D3 supplements for a period of 6+months, has found that the women who took these showed better well-being scores as opposed to those that didn’t take vitamin D3 (placebo group).
Blood clotting. The main duty of Vitamin K in the blood is to help regulate blood clotting and therefore stop bleeding through binding calcium ions and activating various factors and enzymes.
Bone health and bone problems prevention. Vitamin K is a considered to be a factor that works along with vitamin D to promote health calcium levels and storage of minerals in the bone tissue as well as bone density12.
Heart function. Vitamin K is examined in some studies for its role to treat or prevent heart problems in ill and healthy/fit people alike. Cardiologist professor Dr. Dennis Goodman, reveals in his book Vitamin K2: The Missing Nutrient for Heart and Bone Health, that Vitamin K17 and in particular Vitamin K2 also helps support cardiovascular health by preventing unwanted calcium deposits from blocking the arteries, which of course helps prevent atherosclerosis. Another study has found that in healthy individuals who exercise14, Vitamin K2 supplements taken for 8 weeks were linked with enhanced cardiovascular function e.g circulation, oxygen supply, respiratory rates as opposed to the placebo control group.
The link between Vitamin K and Vitamin D absorption
Both of these Vitamins, as we’ve seen earlier have similar roles in help maintaining bone and cardiovascular health and sometimes work synergistically to support these functions. In fact Vitamin D3 is a natural partner of K2 when it comes to enhancing calcium absorption and storage in the bones15. But not only this, this powerful duo helps regulate calcium and prevent it from accumulating in the wrong place, like arteries for example, causing problems.
This is why it is often recommended to take calcium with these vitamins to allow its proper absorption.
Additionally some experts suggest that vitamin D supplementation taken along with vitamin D can also reduce the risk of toxicity, resulting from high calcium levels16.
Does the Vitamin K type matter in its action?
Vitamin K is naturally and synthetically available in various forms such ahs Vitamin K1 and Vitamin K2 (Menaquinone). The first is synthesized in plants and the second (Vitamin K 2) is found in animal products and consists of different vitamin forms called “menaquinones” starting from 1 to 14. The most common forms of vitamin K2 are MK4, MK7, and MK9. The difference in number is based on the isoprenoid chemical chains to its molecule. The biggest the number is, the longest its half life (the duration the vitamin stays active on the blood). Therefore, when seeking a vitamin K2 supplement, it more optimal to seek for forms with longer chain acids like MK7 and MK9 for optimal benefits.
MK7 form of Vitamin K2 is probably the most optimal when it comes to biological activity as it has a half life of 72 hours as opposed to 1.5 hours of MK4. This allows better distribution in the system and activation of additional K-2 dependant proteins18. MK-7 is naturally derived from natto and therefore the most popular form we use in our Oxford Vitality D3/K2 formula.
In general, both Vitamins D and K work in conjunction to promote bone and cardiovascular health among others and are best taken together to regulate calcium absorption and storage in the right places.