Vitamin D and K: a synergistic combination

Research is pointing to vitamin D and K together providing numerous health benefits, including stronger bones

The body needs certain vitamins and minerals to function at optimal levels. Some of these nutrients are water-soluble, traveling to the cells and organs primarily via the bloodstream with any excess amounts excreted in the urine. Others are fat-soluble, absorbed by the lymphatic system with extra intake stored in fat. Two that fall into the second category are vitamin D and K.

Both serve important functions on their own yet may provide an even greater punch when taken as a combination supplement.

Vitamin D benefits

Vitamin D is best known for its role in bone health. The Office of Dietary Supplements (ODS) adds that not getting enough of this key vitamin can impact muscles as well, citing that inadequate intake “can adversely affect muscle strength and lead to muscle weakness and pain (myopathy).”

Another reason to meet vitamin D intake requirements is that it helps promote the absorption of calcium. Like vitamin D, calcium also supports the growth and regeneration of healthy bones. But it serves additional purposes as well.

Although not all research is conclusive, obtaining adequate calcium may help prevent cancer in the colon and rectum according to research published in Gastroenterology. Calcium intake has also been associated with a reduction in the formation of kidney stones.

Importance of vitamin K

Vitamin K is an additional fat-soluble vitamin that offers its own benefits. An article published in the Journal of Clinical Densitometry explains that vitamin K makes osteocalcin in the bone functional and may potentially reduce the risk of hip fractures in older adults.

Other studies have looked at the effect that vitamin K has on cardiovascular health. One in Current Nutrition Reports indicates that, while more trials need to be conducted, there is evidence of this vitamin serving as an anti-inflammatory, helping to protect against age-related cardiovascular disease.

Still more pieces of research have found that taking a vitamin K2 supplement could improve insulin sensitivity, making it beneficial for the prevention and/or treatment of type 2 diabetes.

Vitamin D and K are combined

If vitamin D and K provide numerous health benefits on their own, what happens when they are combined? According to some research, even stronger bones.

Osteocalcin is a protein hormone found in the bone. Also known as bone gamma-carboxyglutamic acid-containing protein (BGLAP), osteocalcin is produced by osteoblasts, which are the cells that form and build new bones.

A study published in Calcified Tissue International reported that when vitamin K2 is in the presence of the active form of vitamin D3 (1 alpha,25-dihydroxyvitamin D3, or 1,25(OH)2D3 for short), the mineralization in bones is different than when vitamin K2 appears alone. Specifically, the vitamin D and K combination was more effective at inducing mineralization at the cellular level.

Other pieces of research stress how important both vitamins are for optimal skeletal structure and function. Each on its own has been named as being important for bone strength and fracture prevention, especially in cases of osteoporosis. This suggests that taking them together could provide the best internal environment for maximal bone health.

Another study, this one published in 2017 in the journal Hypertension, noted that when both vitamin D and vitamin K levels are low, there is an increased risk of high blood pressure and, subsequently, a greater risk of hypertension. The Centers for Disease Control and Prevention states that almost half of U.S. adults have hypertension or are taking medication to treat this condition. Thus, increasing the levels of both of these vitamins could be beneficial to a large number of people.

Perhaps most concerning is a 2021 study in the European Journal of Nutrition which connects low levels of vitamin D and K with greater risks of all-cause mortality. It also linked inadequate D and K status with increased cardiovascular mortality and cardiovascular events, specifically.

Finding a combination supplement

Patients with low levels of vitamin D and K can bolster their intake by taking a combination supplement. This offers more convenience than consuming each on its own, also potentially providing money savings by purchasing one product versus two.

Choosing brands made by reputable and trusted manufacturers offers greater assurance that the vitamins they contain are higher in quality, safer, and potentially more effective. Look for supplements that are third-party tested as this verifies that the product contains what it says on the label and nothing it doesn’t.