The Sunshine Hormone: Why Vitamin D Matters

Summer is one of the best times of year to enjoy the outdoors—whether you're spending time at the beach, gardening, taking walks, or playing with your family. It also happens to be one of the easiest times to naturally boost one of the body's most important hormones: vitamin D.

Many people are surprised to learn that vitamin D is actually considered a hormone rather than a true vitamin. Like thyroid hormone, estrogen, testosterone, and other hormones, vitamin D acts as a messenger, helping regulate countless functions throughout the body. In fact, virtually every cell contains vitamin D receptors, highlighting just how essential it is for overall health.

One patient I recently saw illustrates this perfectly. Her blood work looked excellent overall, but her vitamin D level measured just 36 ng/mL. Although this falls within many laboratory reference ranges (typically 30-100 ng/mL), she struggled with significant fatigue. Because I felt her level was less than optimal, I administered a 50,000-unit vitamin D injection. When she returned several weeks later, the change was remarkable. She reported dramatically improved energy and said she felt better than she had in years. She was so pleased with the results that she requested another vitamin D injection.

While everyone's needs are different, many adults require approximately 5,000-10,000 IU of vitamin D daily to maintain healthy levels, especially if they spend much of their time indoors or avoid sun exposure.

Vitamin D plays a critical role in energy production, immune function, bone health, muscle strength, and many other metabolic processes. When vitamin D levels are low, fatigue is often one of the first symptoms people notice. Research continues to explore vitamin D's role in supporting immune health, cardiovascular wellness, and overall longevity.

Some physicians have also investigated high-dose vitamin D protocols for autoimmune diseases. For example, Professor Cicero Coimbra, a neurologist in São Paulo, Brazil, developed what is commonly known as the Coimbra Protocol, which uses carefully monitored, very high doses of vitamin D in selected patients with autoimmune conditions. While many patients have reported encouraging results, these protocols remain controversial and should only be undertaken under the supervision of experienced healthcare professionals because of the potential risks associated with excessive vitamin D levels.

One of the best natural ways to support healthy vitamin D production is simple—spend time outdoors. During the summer months, brief periods of midday sun exposure, generally between 10:00 a.m. and 2:00 p.m., can stimulate vitamin D production in the skin. Because sunscreen significantly reduces this process, some individuals choose to spend a short amount of time in the sun before applying sun protection. The appropriate amount of exposure depends on your skin type, location, and personal risk factors.

If you are taking vitamin D supplements, it is important to work with your healthcare provider. Monitoring your vitamin D level, calcium level, and overall health helps ensure you are receiving the right amount safely.

This summer, make it a goal to spend a little more time outdoors. Fresh air, physical activity, and healthy sunshine can all be part of a simple strategy to support your health and well-being.

Have a healthy and enjoyable summer!

– John Young, MD - 727-545-4600, YoungFoundationalHealth.com