Sunshine Month and Nurses Week Collide: Are Our Nurses Missing the Light?

Published on May 7, 2026

Rethinking the Health Consequences of Indoor and Shift Work

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by Beth S. Sanford, DNP, RN, Director of Education and Clinical Practice at GrassrootsHealth

Sunshine Month is a time to recognize the powerful role sunlight plays in human health while inviting an important question:

What happens when a profession is built around being indoors?

During Nurses Week (May 6th to May 12th), we celebrate the dedication and sacrifice of nurses. And since it is also Sunshine Month, we are given an opportunity to ask how healthcare systems can better support the health of the workforce itself with opportunities for exposure to daylight.

For nurses and nursing students, limited sun exposure is not incidental, it is structural. Modern healthcare environments are highly artificial from a biological perspective, with long hours under fluorescent lighting, limited daylight exposure, overnight shifts, and minimal time outdoors. Meanwhile, human physiology evolved in close relationship with natural light-dark cycles and regular sunlight exposure. Long work hours, extra shifts, indoor environments, night or rotating schedules, and irregular sleeping patterns reduce opportunities for the healthcare workforce to receive meaningful sunlight exposure. Over time, this pattern leads to sunshine deficiency, identified by lower vitamin D levels and a largely unrecognized and underappreciated occupational health risk.

Sunlight, Vitamin D, and Cellular Health

Sunlight, specifically ultraviolet B (UVB) radiation, is the body’s primary source of vitamin D. When UVB rays reach the skin, they initiate vitamin D synthesis, supporting:

• DNA health and repair
• Circadian rhythm
• Immune regulation
• Neuromuscular function
• Cognitive and mental well-being
• Physical performance and stamina

Importantly, vitamin D production from the sun depends on timing, duration, skin exposure, and individual factors such as skin type, latitude, and season.

Findings From Our Nurses Study: A Workforce Below Optimal Levels

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In our pilot study of nurses and nursing students (n=42), we found the following:

• Average vitamin D level: 20.7 ng/mL
• 55% deficient (<20 ng/mL)
• 41% insufficient (20–39 ng/mL)

Notably, disparities were observed across groups: Black participants had the lowest average vitamin D levels (16.2 ng/mL), compared to 22.6 ng/mL among Caucasian participants. Both were well below optimal levels, but with Black participants at even greater risk.

Equity Insight: Lower vitamin D levels among individuals with darker skin highlight the need for personalized strategies in both nursing workforce and student health.

These findings are consistent with global research demonstrating high rates of deficiency among nurses, healthcare workers, and college/healthcare students (Hattapornsawan et al., 2012; Beloyartseva et al., 2012; Mahdy et al., 2010; Sowah et al., 2017; Cress et al., 2015).

Occupation Influences Risk of Sunlight and Vitamin D Deficiency

Should certain occupations have specific guidelines and recommendations when it comes to sun exposure and vitamin D? Several studies suggest so.

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A large systematic review by Sowah et al. (2017) examining vitamin D status across different occupations found that indoor and shift-based professions consistently carried the highest risk for vitamin D deficiency. Among all occupations studied, deficiency rates were highest in shift workers (80%) and indoor workers (78%), while outdoor workers had significantly higher vitamin D levels overall. Healthcare professionals were also identified as a particularly vulnerable group, with deficiency rates reported in 72% of healthcare students, 65% of medical residents, and 43% of nurses. These findings reinforce the idea that occupational patterns, especially long hours indoors, rotating night shifts, and reduced daylight exposure, can substantially limit sunlight-derived vitamin D production and contribute to chronically low vitamin D levels, as well as additional health deficits resulting from a lack of exposure to sunlight.

These findings suggest that sunlight exposure and vitamin D optimization should be considered an important component of occupational wellness strategies for healthcare workers and other predominantly indoor professions.

Sunlight Deficiency is Much More than Vitamin D Deficiency

Sunlight is much more than a source of vitamin D; natural light during the day is a biological signal that helps regulate circadian rhythm, sleep-wake cycles, mood, metabolism, cognitive alertness, and cellular function. For nurses working long indoor hours or rotating shifts, reduced exposure to natural daylight may contribute to a broader form of biological light deficiency beyond vitamin D deficiency.

“Sunlight is not only a source of vitamin D – it is a fundamental regulator of time, biology, and mental health.” Dr. Alexander Wunsch

Additionally, human health depends not only on exposure to daylight, but also on exposure to true nighttime darkness, which supports melatonin production and cellular repair processes. Disruption of these natural light-dark cycles, common among shift workers, healthcare professionals, and individuals exposed to artificial light late into the evening, has been associated with increased risks of sleep disturbances, depression, anxiety, fatigue, burnout, and broader mental and physical health challenges – many of which are highly prevalent among nurses.

Why This Gap Matters for Performance and Learning

Vitamin D and sunlight deficiency are not only long-term health issues; both affect day-to-day function, performance, and resilience.  Low 25(OH)D serum concentrations and vitamin D deficiency have been associated with:

• Reduced cognitive performance (Bartali et al., 2014)
• Student academic stress and poor academic performance (Almuqbil et al., 2023; AlZahrani & Oommen, 2022; Hassan et al., 2023; Kusmiyati et al., 2020)
• Depression and mood disturbances (Bahnam et al., 2016; Almuqbil et al., 2023)
• Pain (Madani et al., 2014; Masoudi Alavi, et al., 2015b)
• Fatigue (Khamis et al., 2020; Masoudi Alavi et al., 2015)
• Reduced physical performance and increased musculoskeletal injuries (Yoon et al., 2021)
• Poor health-related quality of life (Khamis et al., 2020)
• Decreased feelings of self-efficacy (AlZahrani & Oommen, 2022)

For nurses, this may influence:

• Focus and clinical decision-making in high-stress environments
• Emotional resilience and burnout
• Physical stamina
• Workplace injuries
• Patient safety
• Medication errors

In addition, for new nurses and nursing students, the implications extend into learning success:

• Memory and recall, essential for mastering complex clinical knowledge
• Concentration and learning efficiency
• Academic progression and readiness for practice

Optimizing vitamin D may be one of the simplest ways to support both nurse performance and student success.

Burnout, fatigue, staffing shortages, and workforce retention remain major challenges across healthcare systems. While these issues are complex, supporting biological resilience through measurable and modifiable factors such as vitamin D status may represent a simple but overlooked opportunity to support workforce well-being. For shift workers, natural daylight is often missing completely, yet it is one of the body’s primary regulators of circadian rhythm, influencing sleep quality, cortisol balance, energy levels, mood, and cognitive performance. In other words, chronic disruption of normal light exposure patterns may compound fatigue, burnout, and impaired recovery.

A Missed Opportunity

Workforce and student health strategies often focus on hydration, ergonomics, and infection prevention, but rarely include sunlight exposure or vitamin D status. Fortunately, increasing sunlight exposure and vitamin D levels is easily modifiable, measurable and treatable. This makes it one of the most practical and scalable opportunities for improving workforce and academic health.

What Can Be Done?

For Individuals (Nurses and Nursing Students)

• Spend safe, intentional time in the sun, particularly during mid-day hours when UVB is available
• Avoid sunburn while allowing adequate exposure for vitamin D production
• Understand your personal risk factors (skin type, schedule, geography) and don’t burn your skin
• Get tested to determine your current vitamin D level and if you are getting enough from sunshine exposure – test through your healthcare provider or with a home blood spot test through grassrootshealth.net (as part of our D*action study) or checkyourd.org
• Use evidence-based supplementation when needed
• Reassess levels periodically to maintain optimal status

Start with personalized tools:

• Discover your personalized risk of vitamin D deficiency and insufficiency with our short Vitamin D Deficiency Risk Assessment Quiz
• Order your home vitamin D test at grassrootshealth.net or checkyourd.org
• Calculate your personalized dose of vitamin D with our Vitamin D*Calculator

For Employers and Nursing Programs

Healthcare organizations and academic institutions have a unique opportunity to address this modifiable risk factor:

• Incorporate vitamin D and sunlight education into wellness programs and curricula
• Provide access to routine vitamin D testing, especially for shift workers
• Integrate vitamin D and exposure to daylight into fatigue, burnout, and workforce well-being initiatives
• Support evidence-based supplementation guidance
• Include vitamin D metrics in quality improvement efforts

Employers: Encouraging sensible and intelligent sunshine exposure along with vitamin D optimization may be some of the simplest, most cost-effective strategies available to support workforce health, performance, and retention.

A Call to Action

Sunshine Month reminds us that sunlight is not just environmental; it is a biological necessity. For nurses and nursing students, limited sun exposure is not a lifestyle choice, it is an occupational reality. Recognizing this allows us to take meaningful action.

Nurses spend their careers caring for others during some of life’s most difficult moments, often while sacrificing their own opportunities for rest, recovery, and time outdoors in natural light. Recognizing the importance of sunlight and vitamin D is one small but meaningful way to support the health of the healthcare workforce itself. Our study highlights a clear and actionable issue:

When nurses and nursing students lack sunlight, they lack vitamin D – a simple, measurable, and modifiable biological factor with meaningful implications for individual health, workforce performance, and patient safety.

Bringing sunlight and its downstream health effects back into the conversation represents a practical and powerful step toward improving both workforce well-being and overall health.

About the Author

Dr. Beth Sanford completed her Doctor of Nursing Practice from Rasmussen University with a specialty in Public Health and Policy, focusing on vitamin D translational research. Beth has served vulnerable populations inside and outside the USA since 1996. Currently, she is nursing faculty in the graduate nursing department at Galen College of Nursing. She obtained a post-graduate certificate in Applied Clinical Nutrition to better educate colleagues, patients, and the public about the principles of integrative nutrition. Beth is the lead investigator for GrassrootsHealth’s North Dakota Vitamin D project, and she is serving as the President of the North Dakota Nurses Association and North Dakota Center for Nursing. She advocates for health equity and vitamin D awareness, and volunteers mentoring new nurses and nursing students. Dr. Sanford became passionate about sunlight, vitamin D and population health after her daughter experienced a health crisis accompanied by extremely low vitamin D serum concentrations. You can read more about her research here: Beth SANFORD | Director of Education and Clinical Practice | Doctor of Nursing Practice | Research | Research profile

To learn more about the study, read the study abstract here: (PDF) Vitamin D Status Among Nurses and Nursing Students in a Northern Midwest State: A Pilot Study

Make Sure You Are Getting Enough of Both Sunshine & Vitamin D

It is important to incorporate safe, sensible sun exposure into a regular routine, just as it is important to make sure you are getting enough vitamin D.  Because the sun produces many health-benefiting molecules in addition to vitamin D, sunshine exposure cannot be replaced with taking a supplement.

It is also important not to stop supplementing with vitamin D during the summer.  Most people do not make enough vitamin D from sunshine alone, due to their lifestyle and other factors, and therefore must rely on supplementation to maintain optimal vitamin D levels of 40-60 ng/ml (100-150 nmol/L).

This Sunshine Month, get 10% off your home blood spot test kits PLUS the free Sunshine eBook when using the code SUNMONTH26 at checkout.  Or, save on 2 Vitamin D test kits (for before and after summer sun) plus the Sunshine eBook with our Sunshine Month Bundle here!

Test Your Levels Today!

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Measure Your Vitamin D Level Today

Having and maintaining healthy vitamin D levels and other nutrient levels can help improve your health now and for your future. Choose which additional nutrients to measure, such as your omega-3s and essential minerals including magnesium and zinc, by creating your custom home test kit today. Take steps to improve the status of each of these measurements to benefit your overall health. With measurement you can then determine how much is needed and steps to achieve your goals.  You can also track your own intakes, symptoms and results to see what works best for YOU.

Enroll in D*action and Test Your Levels Today!

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References

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AlZahrani, W. I., & Oommen, A. (2023). Role of vitamin D in the academic performance of health sciences students in Saudi Arabia. Arab Gulf Journal of Scientific Research, 41(1), 40-47.

Bahnam, B., Semnani, V., Hadadnia, F., & Mirmohammadkhani, M. (2016). Vitamin D serum levels in nurses and its association with depression. Koomesh, 17(2), e151347.

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Beloyartseva, M., Mithal, A., Kaur, P., Kalra, S., Baruah, M. P., Mukhopadhyay, S., Bantwal, G., & Bandgar, T. R. (2012). Widespread vitamin D deficiency among Indian health care professionals. Archives of Osteoporosis, 7(1–2), 187–192. https://doi.org/10.1007/s11657-012-0096-x

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Hassan, A.A.; Elbashir, M.I.; Al-Nafeesah, A.; AlEed, A.; Adam, I. Association between Serum 25-Hydroxyvitamin D Concentrations and Academic Performance among Adolescent Schoolchildren: A Cross-Sectional Study. Nutrients 2023, 15, 4552. https://doi.org/10.3390/nu15214552

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