Recent studies have revealed that vitamin D and calcium supplements might offer a promising strategy for managing blood pressure among older adults, especially those with obesity. A study published in the Journal of the Endocrine Society examined the effects of vitamin D supplementation in 221 overweight seniors in Beirut, Lebanon, and explored how varying doses of vitamin D could affect their health, particularly in relation to blood pressure.
Key findings from the study
Dr. Ghada El-Hajj Fuleihan, a professor of medicine at the American University of Beirut, led the study and noted that vitamin D supplementation, especially when paired with calcium, could help lower blood pressure in older adults with obesity. This is particularly significant given that nearly one in five older adults in the U.S. is vitamin D deficient and does not meet the recommended daily intake of 600 to 800 IUs.
Research has long suggested a link between vitamin D deficiency and high blood pressure, but the findings have been inconsistent. This study provides new insight into how vitamin D supplementation might help reduce blood pressure, especially in those who are vitamin D deficient.
Study design and results
The study included participants aged 65 and older with a body mass index (BMI) over 25. They were divided into two groups: one group received a lower dose of vitamin D (600 IU), while the other received a higher dose (3,750 IU). Both groups also received a daily calcium supplement of 1000 mg. Over six months to a year, researchers tracked the participants’ blood pressure.
- The high-dose group saw a reduction in systolic blood pressure by 4.2 mmHg.
- The low-dose group experienced a 2.8 mmHg decrease.
- Diastolic blood pressure also improved, with the high-dose group showing a 3.02 mmHg decrease, and the low-dose group seeing a 2.6 mmHg drop.
Interestingly, significant improvements in blood pressure were only observed in the subgroup of participants classified as obese (BMI of 30 or higher). These individuals benefitted from both low and high doses of vitamin D, which suggests that their initially lower vitamin D levels may have played a role in the positive effects.
Limitations of the study
While the findings are promising, experts caution that the absence of a placebo group makes it difficult to draw definitive conclusions. Dr. JoAnn Manson from Harvard Medical School highlighted that without a control group, it’s hard to determine whether the blood pressure reductions were directly due to vitamin D supplementation or influenced by other factors.
The study was originally designed to assess the impact of calcium and vitamin D on bone density and insulin resistance, not blood pressure. Therefore, the blood pressure analysis is considered exploratory, requiring further research to confirm these findings.
Understanding vitamin D’s role in heart health
While observational studies have linked low vitamin D levels to an increased risk of cardiovascular diseases, including heart attacks and strokes, clinical trials have not consistently shown significant cardiovascular benefits from vitamin D supplementation. Dr. Manson’s meta-analysis of 21 trials found no evidence to suggest that vitamin D supplementation reduces the risk of cardiovascular events.
Experts believe the relationship between vitamin D and heart health may be influenced by other factors, such as lifestyle choices. People with poor heart health may engage in less outdoor activity and follow unhealthy diets, which can contribute to low vitamin D levels.
Recommendations for vitamin D intake
For individuals who do not show symptoms of vitamin D deficiency, the U.S. Preventative Services Task Force has stated that there is insufficient evidence to recommend routine screening or supplementation. However, for those found to be deficient, vitamin D supplementation can be beneficial. Dr. Hall recommends starting with a daily dose of 1,000 IU and stresses the importance of obtaining vitamin D through sun exposure and diet.
Foods rich in vitamin D
- Fortified milk
- Fortified cereal
- Cod liver oil
- Trout
- Salmon
- Mushrooms
- Eggs
Conclusion
Vitamin D and calcium supplements may offer benefits for older adults with obesity, particularly in managing blood pressure. However, further research is needed to clarify the effectiveness of these supplements in blood pressure control. Individuals considering supplementation should consult healthcare professionals to determine the best course of action based on their unique health needs.
