Clinical research

Analysis of data from the VITAL trial found that 4-years of supplementation with 2000 IU/day vitamin D3 reduced telomere attrition by 140 bp, suggesting that vitamin D3 daily supplementation might have a role in counteracting telomere erosion or cell senescence.

About the book In In Defense of Sunlight, science journalist Rowan Jacobson makes the case that the public health conversation around sun exposure has been incomplete. Yes, too much sun carries real risks. But avoiding it entirely comes at a biological cost that most people don't fully appreciate. Drawing on decades of research, Jacobson explores how UVB light does far more than produce vitamin D - driving hormone production, supporting the microbiome, releasing nitric oxide, and influencing mood, immunity, and cardiovascular health through pathways that oral supplements simply can't replicate. The book features a foreword by Dr. Richard Weller, a leading dermatologist and researcher whose work on nitric oxide and sunlight helped reshape how scientists think about UV exposure and human health. Where the science leads Solius was built around the same body of research Jacobson explores in the book. People are increasingly caught between two competing realities. On one hand, the scientific evidence continues to show that sunlight plays an important role in human health. On the other, excessive sun exposure carries well-established risks, including skin damage and skin cancer. For decades, the conversation has largely been framed as a choice between getting the benefits of sunlight and avoiding its risks. Solius was designed to solve that dilemma. By delivering a personalized dose of targeted UVB light, it provides a way to access the biological benefits associated with sunlight while dramatically reducing unnecessary UV exposure. The challenge has always been dosing. The right amount of UVB is different for every person. Skin tone, age, geography, season, weather, and prior sun exposure all influence how much UVB someone should receive. Too little may provide little benefit, while too much can increase risk. Solius solves that problem by automatically measuring the user, calculating a personalized dose, and delivering it consistently in just a few minutes each week. About the author Rowan Jacobsen writes about science and nature and the less-explored corners of the world for Harper’s, Outside, The Atlantic, Scientific American, Smithsonian, The New York Times, The Washington Post, MIT Technology Review, Businessweek, and others, and his work has been anthologized in The Best American Science & Nature Writing and other collections. He has received awards from the James Beard Foundation, the Society of American Travel Writers, and the Overseas Press Club. He is the author of nine books, including A Geography of Oysters, Fruitless Fall, and Truffle Hound, several of which have been named to Best Book of the Year lists by The Washington Post, The Wall Street Journal, The Boston Globe, NPR, and Publishers Weekly. He has performed with Pop-Up Magazine, lectured at Harvard and Yale, and appeared on CBS, NBC, and NPR. He has been an Alicia Patterson Foundation Fellow, writing about endangered diversity on the borderlands between India, Myanmar, and China; a Knight Science Journalism Fellow at MIT, focusing on the environmental and evolutionary impact of synthetic biology; and a Nova Media Fellow, researching the science of sun exposure.

UVB exposure can influence cardiovascular and metabolic health through nitric oxide (NO)–mediated pathways that do not require vitamin D synthesis. This review summarizes the systemic effects of UV radiation on hypertension and several metabolic diseases such as obesity and diabetes. UVB stimulates NO production in the skin, which enters circulation to promote vasodilation, lower blood pressure, and reduce cardiovascular risk.

This paper describes how UVB activates a broad range of hormones, neurohormones, neurotransmitters, and immune mediators that influence mood, stress balance, and neuroprotection. The paper further shows that these UVB-induced signals are tightly coordinated by a skin-based neuro-immuno-endocrine system, which processes and integrates them before sending them throughout the body. These signals travel to the brain and other organs through both the bloodstream and direct nerve pathways, where they help regulate whole-body homeostasis. In doing so, UVB exposure can modulate immune activity, activate central stress-response systems, and influence the function of multiple organ systems.

This research reviewed ecological studies to investigate geographical variations of UVB exposure, vitamin D, and cancer incidence and mortality rates. They found strong inverse correlations with solar UVB for 15 types of cancer: bladder, breast, cervical, colon, endometrial, esophageal, gastric, lung, ovarian, pancreatic, rectal, renal, and vulvar cancer, and Hodgkin's and non-Hodgkin's lymphoma. They also found that weaker evidence exists for an association between solar UVB and nine other types of cancer: brain, gallbladder, laryngeal, oral/pharyngeal, prostate, and thyroid cancer; leukemia; melanoma; and multiple myeloma.

A prospective clinical safety study supported by IQVIA contract research organization evaluated 53 healthy subjects of various skin types and baseline vitamin D status over 15 weeks using SOLIUS PRO at varying doses, frequency, intensity, and surface area. An increase in 25(OH)D was observed in 79% of all subjects regardless of starting vitamin D status and in 89% of subjects with a starting vitamin D status of deficient or insufficient. The once-weekly torso-only group achieved the greatest increase (average 9.91 ng/mL). No serious adverse events occurred. This study demonstrated that regular use as indicated of the SOLIUS PRO reliably stimulates endogenous vitamin D production. These findings validated that SOLIUS can safely and effectively elevate serum vitamin D levels using short-duration, sub-erythemal UVB doses.

This study that looked at the mental health of operating room nurses, who had little sunlight exposure due to their long work hours, found that this population had poorer mental health than the general population. The study found that poor mental health was associated with less sunlight hours, worse sleep regularity, and increased chronic disease. As the duration of sunlight exposure increased, survey respondents’ mental health status improved.

This review examines the dual role of UVB radiation in health and disease, focusing on the mechanisms of vitamin D3 production in the skin, the epidemiology of skin cancer, and the protective roles of vitamin D3’s photoproducts and its active metabolite, 1,25-dihydroxyvitamin D3. While excessive sun exposure is linked to skin cancer through direct DNA damage and oxidative stress, insufficient UVB exposure limits the production of vitamin D3 which acts as a protector of skin health through anti-inflammatory activity and DNA repair mechanisms.

In this study that looked at UV light exposure and mortality data for over 500,000 individuals, UV exposure was inversely associated with all-cause, cardiovascular disease (CVD) and cancer mortality. Solarium users were also at a lower risk of non-CVD and non-cancer mortality.

This review argues that current clinical guidelines for vitamin D supplementation, which focus mainly on skeletal health, overlook a wide range of endocrine, genomic, and extra-skeletal benefits that vitamin D offers for immune, cardiovascular, metabolic, and overall health. The authors recommend developing updated guidelines that incorporate evidence beyond bone effects to better prevent disease and improve public health outcomes.

This study found that mice with increased availability of vitamin D display greater immune-dependent resistance to cancers. Similarly, in humans, vitamin D induced genes correlate with improved response to immune checkpoint inhibitor treatment, as well as with immunity to cancer and increased overall survival. In mice, resistance is attributable to the activity of vitamin D on intestinal epithelial cells, which alters microbiome composition in favor of Bacteroides fragilis, which positively regulates cancer immunity. These findings indicate a connection between vitamin D, microbial commensal communities, and immune responses to cancer.

This double-blind, randomized, placebo controlled clinical trial found that high-dose oral vitamin D supplementation (100,000 IU of vitamin D twice per month) reduced disease activity in clinically isolated syndrome and in early relapsing-remitting multiple sclerosis when intervention was started within 90 days of the start of clinically isolated syndrome.

Solar UV has been inversely correlated with geographical and seasonal variation in many health conditions, including cardiovascular disease and respiratory infections. This article discusses how this effect could be impacted by various factors, including nitric oxide production, heat, vitamin D, and gene expression. The author, vitamin D expert William Grant, recommends increasing exposure to summer sunlight without sunburn to improve health.

This study suggests that 820,000 deaths per year in the United States and Europe and an increased incidence of breast cancer, colorectal cancer, hypertension, cardiovascular disease, metabolic syndrome, multiple sclerosis, Alzheimer's disease, autism, asthma, type 1 diabetes, and myopia could be attributed to insufficient sun exposure.

This review article by ultraviolet expert Richard Weller highlights that while ultraviolet radiation is known as a skin carcinogen, many studies correlate sun exposure with reduced all-cause, cardiovascular, and cancer mortality. The paper suggests that sunlight may confer health benefits beyond vitamin D synthesis, such as the photomobilization of nitric oxide from skin stores, which can reduce cardiovascular morbidity.

This review explores the gut-skin axis, describing the interaction that occurs between the skin and the gastrointestinal tract. Recent studies show that exposing the skin to ultraviolet B-light can beneficially modulate both the gut microbiome and intestinal health.

This analysis of data from almost 30,000 women from the Melanoma in Southern Sweden (MISS) cohort found that nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking. Moreover, compared to women with the highest sun exposure, life expectancy for women who avoided the sun was shorter by up to 2.1 years.

This study of 12,388 dementia-free participants at baseline found that vitamin D supplementation was associated with significantly longer dementia-free survival and lower dementia incidence rate than no supplementation over 10 years. Vitamin D supplementation was associated with 40% lower dementia incidence. These results suggest that vitamin D may play a role in dementia prevention, especially for those who are at high-risk.

The WHO estimates that lack of sunlight contributes to 3.3 billion lost years of healthy life globally, while excessive sun exposure accounts for only 0.1% of worldwide lost years of healthy life.

Vitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes.

This review article discusses the gut microbiota and vitamin D as an emerging and vital axis influencing immune aging and age-related diseases. It highlights the dual role of gut microbiota in shaping host immunity and regulating vitamin D metabolism, alongside the significant immunomodulatory potential of vitamin D in maintaining intestinal homeostasis and barrier integrity. The findings suggest that vitamin D deficiency and gut dysbiosis accelerate immunosenescence and inflammageing, contributing to unhealthy aging and increased risk of age-related diseases.