A growing body of research suggests that vitamin D, often known as the “sunshine vitamin,” may play a significant role in lowering the risk of major cardiovascular events, including stroke. According to a new narrative review published in the journal Nutrients and reported by EatingWell (eatingwell.com), regular supplementation of vitamin D could reduce the risk of stroke by up to 17%. This revelation is especially relevant for Thai readers, given the high prevalence of heart disease and stroke in Thailand and Southeast Asia, where diet, lifestyle, and even cultural attitudes toward sun exposure can influence vitamin D status.
Heart disease remains the leading cause of death globally, including in Thailand, where non-communicable diseases such as ischemic heart disease and stroke account for a significant proportion of mortality (WHO Thailand NCD Profile). With projections indicating a continuous rise in cardiovascular disease, understanding modifiable risk factors, such as nutrition and vitamin deficiencies, is crucial for Thai society, particularly as the population ages.
The narrative review analyzed multiple studies focused on vitamin D and cardiovascular outcomes. While some randomized clinical trials have found that vitamin D supplementation alone does not significantly reduce cardiac events in general populations (Harvard Gazette, 2024), the review identified subgroups that may benefit more. Pregnant women who supplemented vitamin D were found to have up to a 60% lower risk of preeclampsia, a 50% lower risk of gestational diabetes, and a 40% lower risk of preterm delivery. For those living with prediabetes, vitamin D supplementation contributed to a notable reduction in cardiovascular risk. Additionally, individuals already taking statin medications or other cardiovascular drugs experienced a 13-17% reduction in major cardiovascular events when supplementing with vitamin D.
There are some caveats, as highlighted by clinical nutritionists and endocrinologists. While vitamin D’s role in calcium metabolism, bone health, and immune support is well established, the evidence for direct prevention of major cardiovascular events remains limited due to the scarcity of robust randomized controlled trials. One of the most recent systematic reviews of 2025 points to a lack of consensus on whether vitamin D supplementation substantially impacts blood pressure or endothelial function in the general population (PubMed: Effects of Vitamin D Supplementation on Blood Pressure, 2025). Nonetheless, many researchers and medical professionals caution that deficiency in vitamin D is commonly underdiagnosed and may indirectly contribute to obesity, diabetes, and, consequently, elevated cardiovascular risk (CDC, 2025).
For Thai readers, these findings underscore the importance of understanding how lifestyle and environmental factors affect vitamin D synthesis. Despite Thailand’s tropical climate, studies have found that urban lifestyles, extensive use of sunblock, indoor work environments, and cultural preferences for lighter skin—often leading to sun avoidance—can put many urban Thais at risk of vitamin D deficiency (Times of India, 2025). National surveys in Thailand have reported surprisingly high rates of suboptimal vitamin D levels, especially among women and the elderly, who are often less exposed to direct sunlight.
Vitamin D is present in only a handful of foods commonly consumed in Thailand. Natural sources include egg yolks, certain mushrooms, and fatty fish like salmon and mackerel—which, while available, are not staple components of the traditional Thai diet. In urban areas, vitamin-fortified milk and breakfast cereals are sometimes consumed, but often in insufficient quantities to meet daily requirements for high-risk groups such as older adults, children, and pregnant women.
Expert perspectives are divided. According to the Endocrine Society’s 2024 recommendations, routine vitamin D screening is not necessary for most healthy people, and supplementation should be tailored based on testing and clinical need (Oxford Academic, 2025). However, Thai physicians often advise individuals who receive little sun exposure or those with risk factors (pregnancy, older age, osteoporosis, or certain chronic illnesses) to speak with their healthcare provider about monitoring vitamin D status. An official from a major public health hospital in Bangkok emphasizes, “Rather than blanket supplementation, targeted testing can help identify and treat a deficiency before it leads to complications.”
Historical and cultural attitudes also shape public perception. In Thailand, notions of beauty often favor fair skin, encouraging the use of sunscreen and avoidance of the midday sun, both of which reduce natural vitamin D production. Meanwhile, the growing popularity of urban lifestyles and air-conditioned environments means many Thais spend much of the day indoors. These cultural and behavioral factors, when combined with dietary patterns, create a unique regional context for the discussion about vitamin D deficiency and heart health.
Looking ahead, ongoing research may provide clearer answers about who is most likely to benefit from vitamin D supplementation and optimal dosing. The growing elderly population in Thailand, along with epidemic rates of diabetes and hypertension, suggests that cost-effective interventions—including improving vitamin D status—could have important public health impacts. Meanwhile, scientists urge caution against over-supplementation. Because vitamin D is fat-soluble, excessive intake over long periods can cause toxicity, with symptoms ranging from nausea to potentially fatal complications. Health experts recommend regular blood tests for those at risk and that supplementation, if necessary, be monitored by a healthcare professional or registered dietitian.
For practical action, Thai readers should consider modest, regular sun exposure—such as spending 15-30 minutes outdoors in the early morning or late afternoon, with bare arms or legs, several times a week. For those with difficulties accessing sunlight or with dietary limitations, speak to a healthcare professional about whether blood testing or supplementation is warranted. Diet diversification, including more vitamin D-rich or fortified foods, can also help. Pregnant women, older adults, and individuals with chronic illnesses should be especially diligent.
Ultimately, maintaining optimal vitamin D levels is only one component of an overall cardiovascular prevention strategy that includes exercise, balanced nutrition, not smoking, and effective management of blood pressure, blood sugar, and cholesterol. As research continues to evolve, staying informed and working closely with healthcare providers is the best path toward reducing the risks of stroke and heart disease in Thailand.
For further reading, see the original article at EatingWell, recent commentary from Harvard Gazette, and public health guidance from the CDC.