A comprehensive meta-study of 99 randomized, controlled trials from around the world has found that an average supplemental dose of 3,320 IU of vitamin D per day is associated with reduced blood pressure, total cholesterol, hemoglobin A1C, and fasting blood insulin and glucose. The study aimed to distill findings from sometimes conflicting research on the benefits of vitamin D for cardiometabolic health. The authors found that taking a median dose of 3,320 International Units (IU) of vitamin D per day was linked to several significant cardiometabolic benefits, including reductions in blood pressure, cholesterol, hemoglobin A1C, and blood glucose and insulin levels.
The researchers examined the details of 99 randomized, controlled trials involving 17,656 participants from various global locations. By cataloging the differences between the trials that might explain their varying conclusions, the authors were able to re-analyze and compare the data in a more balanced manner. They found that vitamin D supplementation provided the greatest benefit to non-Western populations, individuals with lower circulating vitamin D levels, those with a BMI under 30, and people ages 50 and older. Ethnocultural background, age, body weight, and initial 25(OH)D levels were identified as key factors that influenced the outcomes of the trials.
There is still some uncertainty in the medical community regarding the direct cause and effect relationship between vitamin D supplementation and cardiovascular health. While low serum vitamin D levels are associated with increased cardiovascular risk, it remains unclear whether this is a cause or a consequence of heart disease. However, the data leans towards positive effects on bone health, muscle function, and reduced inflammation, as well as potential benefits for hypertension, diabetes, and lipid levels. Achieving optimal levels of vitamin D for cardiometabolic health may require personalized intervention strategies based on an individual’s ethnocultural background and biological features.
Non-Western populations, individuals with lower levels of circulating vitamin D, those with a BMI under 30, and individuals ages 50 and older are more likely to benefit from vitamin D supplementation according to the meta-study’s findings. Individuals with obesity and low 25(OH)D levels may require higher doses of vitamin D for longer durations to see improvements in cardiometabolic health outcomes. The researchers suggest that personalized intervention strategies, taking into account factors such as ethnocultural background, age, body weight, and initial vitamin D levels, may be necessary to achieve optimal benefits from vitamin D supplementation. While more research is needed to establish definitive cause and effect relationships, the evidence suggests that vitamin D may play a role in maintaining cardiometabolic health.
