Current research suggests that the combined supplementation of both vitamins D and K may exhibit certain synergistic characteristics than either vitamin alone for bone health and cardiovascular function. Vitamin D helps support healthy bone mineralization, calcium homeostasis regulation, and immune health. Vitamin K is a fat-soluble vitamin critical to the carboxylation of osteocalcin in bone and helps support healthy bone density status, blood coagulation, and vascular health. In population studies, concurrent lowered vitamin D and K status has been associated with increased incidences of hypertension and arterial stiffness.

A prospective clinical study by van Ballegooijen and colleagues investigated the potential effect that combined low vitamin D and K status may have on mortality risk. The study involved over 4,700 individuals; approximately 20% of participants had a combined lowered vitamin D and K status. After data analysis, the researchers determined that a combined lowered vitamin D and K status was associated with increased all-cause mortality risk and a non-significant risk for cardiovascular events and mortality.

An animal study explored the potential efficacy of vitamins D and K in the prevention of osteoporosis progression. The largest prevention of bone loss occurred in the combination treatment group, suggesting a potential synergism regarding bone health.

Deficiencies in vitamins D and K are common in individuals with chronic kidney disease (CKD), which affects over 10% of the global population. Lowered vitamin D and K status has been associated with a 150% increased risk of all-cause mortality in individuals who have received a kidney transplant. A review by Ziemińska and colleagues investigated the potential synergy between the two molecules in the presence of CKD. A clinical study involving 172 individuals with stage 3 to 5 CKD reported an association between suboptimal vitamin D and K status and biomarkers related to kidney and bone remodeling. However, more research is needed before clinical conclusions can be made, especially with the complex biochemistry involved with kidney disease. Additionally, more preclinical studies are needed to determine the potential mechanisms of action regarding the potential synergy between vitamins D and K; preliminary studies indicate that more trials are warranted.

While research on this topic needs to be elucidated in further studies, vitamins D and K may help support certain aspects of health. They may help support bone health, cardiovascular function, and a healthy immune response. Sources of vitamin K include green leafy vegetables, fermented foods, and certain gut microbes. Vitamin D can be obtained from sun exposure to the skin, certain foods such as the flesh of fatty fish, and certain fortified foods.

By Dr. C Ambrose, ND, MAT