Exploring the Benefits of Vitamins D3 and K2 for Your Health

Working for WellnessPulse means I am surrounded by wellness enthusiasts, and no wonder I hear people mention vitamin D quite often. Since the sun is rather shy where I live, inspired by all that talk, I decided to get my vitamin D levels checked.

Too low. I was surprised but not shocked. Naturally, this led me to explore the topic of vitamin D in more depth: what happens when you don’t get enough of it and how to boost it. But along the way, I kept coming across another nutrient that often gets overlooked — vitamin K. Turns out these two vitamins are more connected than I realized.

In this article, I will present information I gathered from scientific journals to help you better understand these two vitamins. Moreover, I spoke with various health experts to further expand my knowledge and share some of the most important things to keep in mind when talking about vitamins D and K.

Understanding the basics: what are vitamins D3 and K2?

Both vitamin D and K are fat-soluble vitamins. It means that they can be stored in our bodies — in the liver and fatty tissues, to be precise. Because of that, you do not need to replenish their levels every day like you do with water-soluble vitamins (for example, vitamin C). However, not getting enough of them over time will lead to deficiencies.

Vitamin D is quite unique in the vitamin world because our bodies can produce it when exposed to sunlight. It is also found in animal-derived foods such as liver, butter, and fatty fish. Most foods do not naturally contain a lot of vitamin D unless it is added. Commonly fortified foods with vitamin D include plant-based milks and cereals.

The main difference between vitamins D2 and D3 comes down to their sources: vitamin D2 is found in plant-based foods, while vitamin D3 is found in animal products and is the one that is produced when our skin is exposed to the sun.

Vitamin K is also unique in a similar manner as vitamin D. While we can get vitamin K from food, it is also synthesized in our gut by bacteria. The main sources of vitamin K are green leafy vegetables, vegetable oils, certain fruits (e.g., figs), meat, cheese, eggs, and soy.

Vitamin K1 is found in plant-based foods, while vitamin K2 comes from animal sources. Our gut bacteria also produce vitamin K2.

Working together: the synergistic effect of D3 and K2 for bone health

As I get older, I realize I get rather excited to learn more about bone health — something that was not on my mind in my early 20s. When it comes to bone health, vitamins D3 and K2 stand out in the crowd: the main benefits associated with these vitamins are their ability to support healthy bones through calcium metabolism.

Vitamin D aids calcium absorption, which is crucial for bone mineral density. Vitamin K, on the other hand, acts as a guide for calcium, directing it to the bones and teeth where it is needed most while preventing it from depositing in the blood vessels and soft tissues.

In general, research studies show that taking vitamins D3 and K2 together may help prevent osteoporosis, with the effect potentially greater than taking them separately.

The potential heart health benefits of D3 and K2 together

Vitamins D3 and K2 play distinct yet complementary roles in supporting cardiovascular health. To clarify how they work, I consulted Dr. Gail Clifford, an experienced Internal Medicine Hospitalist and professor of medicine, and asked her to share her insights.

“Vitamin D helps regulate calcium levels in the body, supports immune function, and may help lower inflammation. Some research has linked adequate vitamin D levels to a reduced risk of high blood pressure and better vascular health,” she explains to our readers.

“While these findings are promising, large clinical trials have shown mixed results, and most experts agree that vitamin D is more effective at maintaining overall health when used to correct a deficiency rather than as a preventive tool for heart disease,” adds Dr. Gail Clifford.

As mentioned in the previous section, vitamin K is essential for human health as it directs calcium to the bones and teeth. This may help prevent the calcification of arteries and, thus, can help maintain a cardiovascular system. “Several studies suggest that low vitamin K intake is associated with an increased risk of vascular calcification, a known contributor to heart disease,” further expands Dr. Gail Clifford.

Getting enough: food sources and supplementation

As mentioned above, vitamins K and D are synthesized in our bodies, meaning that we can produce these vitamins under certain conditions. However, it is still possible to be deficient in them, so incorporating foods that are rich in vitamins D and K can be beneficial.

In some cases, supplementation may also be needed. For this section, I asked Dr. Gail Clifford to clarify when. As she explained, supplements are typically recommended for individuals not obtaining enough nutrients from their diet or sunlight or if a blood test indicates a deficiency.

Vitamin D supplements are commonly used by people who spend little time in the sun, have darker skin, are older adults, or have health conditions that make it harder to absorb fat.

Dr. Gail Clifford

Vitamin K supplements may also be considered when someone is not getting enough of it through diet. Moreover, it is considered if the person has a condition that interferes with the absorption of this vitamin. As mentioned by Dr. Gail Clifford, examples of these could be celiac disease or long-term antibiotic use.

“Some people concerned about bone health or vascular calcification, particularly older adults, may also benefit from additional vitamin K2,” adds Dr. Gail Clifford. She emphasizes the importance of consulting your doctor before starting any supplements, particularly if you are taking medications like blood thinners.

Safety and important considerations

While taking vitamin D and K supplements is considered relatively safe, you should be aware of a few considerations.

Can you take too much vitamin D or K?

While you cannot get too much vitamin D or K from natural sources, supplementation might cause toxicity.

Taking too much vitamin D may lead to increased calcium levels in the blood. This could cause side effects such as vomiting, weakness, frequent urination, and bone pain. In more serious cases, it could lead to kidney problems such as kidney stones.

While toxicity from taking too much vitamin K is extremely rare, it can cause side effects such as jaundice, hyperbilirubinemia, hemolytic anemia, and kernicterus. However, to current scientific knowledge, toxicity is associated with menadione, a specific vitamin K3 supplement that is not usually used in humans.

Interactions with prescription drugs

Several prescription drugs might interact with vitamin D or K supplements.

For instance, vitamin K can interact dangerously with warfarin, a blood-thinning medication. Vitamin K is known to reduce the effects of warfarin; thus, it is advised against taking both of them together unless you are under your doctor’s advice and supervision.

Vitamin D interacts with digoxin, a medication for congestive heart failure, and hydrochlorothiazide, a diuretic that decreases urinary calcium excretion. You should consult your doctor if you take any of these medications before taking vitamin D supplements.

Final thoughts

Some of the vitamin D3 and K2 benefits include supporting bone health, cardiovascular health, and the immune system. Although these vitamins can be produced in our bodies and obtained through our diet, some people are still deficient.

If you’re unsure about your levels, a quick blood test and a chat with your doctor can help you decide whether diet or supplements are the best option.