The Secrets of Vitamin Interactions: D3 and K2


“Drink milk, it’s good for your bones”, is a common adage that we have all heard growing up, but the requirements for strong bones doesn’t stop there.  Many areas of your body require a delicate balance of vitamins and minerals, such as the relationship between bone health, calcium, vitamin D3 and vitamin K2 that requires more than just milk. With high occurrences of vitamin K2 deficiency affecting as much as 97% of the elderly population, the deficiency disrupts the careful balance essential for strong bones [1].

Each fall, as the days get shorterbones-compressor.jpg with the diminishing amount of sunlight, the vitamin D3 levels in our blood drop.  Vitamin D3 is synthesized from the transformation of cholesterol through sunlight, which is then absorbed into the blood stream. This important vitamin is brought to the liver and kidneys to be converted to the activated form of vitamin D (calcitriol), which helps regulate calcium levels. In the darker months, many rely on supplements to boost the low vitamin D3 levels in their bodies. 

What Does Vitamin K Do?

In the past, vitamin K was used as a broad classification for vitamins K1, K2, and K3 and it was assumed that your body could convert the different types of vitamin K when needed. Vitamin K1, found in green leafy vegetables, is the most well-known variation and its role in blood clotting has become wrongly synonymous with all variations of the vitamin. The lesser known vitamin K2 also serves many important functions.

K2 is a great companion vitamin; it works well with other vitamins to enable their full effect. Vitamins D3 and K2 are natural complements in the process of calcium absorption. While it is common knowledge that Vitamin D aids in the absorption of calcium that promotes strong bones, people are less aware that vitamin K2 also plays a crucial process in building bones. K2 directs the calcium to your bones, which prevents it from being deposited in other areas of your body.

Excessive calcium intake can be harmful when not absorbed properly, as unused calcium in the bloodstream can create deposits in body tissue and organs, causing diseases like calcified arteries and kidney stones. Vitamin K2 when used in conjunction with D3 keeps your body in balance and prevents the unwanted calcium deposits.  It is important to keep levels of vitamin D3 and K2 at adequate levels when ingesting calcium, as a deficiency in either can cause damage to the cardiovascular system.

winter-in-the-city-compressor.jpgHow to Manage Vitamin Deficiencies

In the winter months, it is much harder to get adequate levels of vitamin D from the sun, as UVB rays weaken and sunlight becomes sparse. In Canada, vitamin D deficiency is a well-known contributor to a range of health conditions that also increases risk of heart disease. This awareness has led to foods fortified with vitamin D like dairy products and cereals. Vitamin D supplements are another common method to ensure your body’s health.

Deficiencies in K2 can lead to increased risk in osteoporosis, as K2 is responsible for developing strong bone-related proteins and reducing the risk of bone defects. Bone density and strength are a result of a mix of nutrients, including K2 and D3. In addition, Vitamin K2 plays a part in tooth health, as it directs calcium to your teeth, which supports its structure and hardness. Recent research has also pointed to vitamins K1 and K2 as factors that help prevent and treat cancers affecting the prostate, blood and bone marrow.

Vitamin K1 deficiency is rare, as the vitamin is easily found in many foods such as kale, spinach, mustard greens, parsley, broccoli, and Brussels sprouts. Vitamin K2 is consumed less often, as it is found in only a few food items. The recommended daily dose of K2 is between 360-500 micrograms per day, which equates to a few ounces of natto (a fermented soy product) or fermented vegetables.  An alternate source is in grass-fed organic animal products like cheese, which requires a daily consumption of about 6 ounces per day, or organ meats that only provide trace amounts of K2.

Vitamin K1 and K2 both have important and distinct functions, yet most people consume very little K2 and 10 times more K1. It is more difficult to include K2 in a diet, as it is only found in a few items, and the taste doesn’t appeal to all people. Supplements that contain both D3 and K2 are convenient when ensuring the adequate amounts of both vitamins.

If you find it difficult to include K2 containing foods in your diet there are great supplements for bones that contain both D3 and K2.


[1] Journal of Human Nutrition & Food Science. Retrieved from

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