Sunshine is critical to good health, and we need to find the right balance. With all the negative press about sun exposure and skin cancer, many people avoid sunshine like the plague out of fear. Others avoid it because of medications or conditions like Lupus. At this time of year, others miss out on sunshine because it’s just too cold to be outside, or in the summer, its too hot to be outside, and everyone stays in their air conditioning. But getting amost no sun may be just as damaging to your health as getting to much sun!
Now, too much sun certainly is not a good thing, and can cause skin lesions and skin cancer. The most risk occurs with many hours of continuous exposure, especially after prolonged periods of no exposure. The darker a persons natural color (more melanin), the less inherent risk they have. Accumulated tan also reduces risk as summer progresses. The most risk happens with getting a bad sun burn at tropical latitudes on lily-white skin that has been indoors or in a cold climate. Chronic exposure for much of every day such as a roofer or lifeguard is risky as well. That said, some moderate sun exposure is actually necessary for good health.
The health benefits of moderate sun exposure fall into 2 categories: vitamin D manufacture and preventing depression and seasonal affective disorder. Vitamin D is critical to proper immune system function, proper metabolism, fat utilization, calcium absorption and osteoporosis prevention, and a host of other biochemical processes in the body. While D supplementation can help with a vitamin D deficiency, our bodies were designed to manufacture vitamin D when sunlight hits our skin, and it is by far the most metabolically available source of D, and hence the healthiest way to get vitamin D.
Sunlight is also closely linked to production of dopamine and serotonin. Interestingly, this mechanism is through receptors in our eyes that are triggered by a certain wavelength of light. Standard indoor lighting is not the right wavelength and will not active serotonin production, only sunlight or special lamps of the right wavelength made to prevent Seasonal Affective Disorder, or SAD, will trigger serotonin production. People in grey, cold northern climates and with very short daylight hours in the winter like Alaska, Canada, Washington, and Finland tend to have much higher incidences of SAD.
So what is safe, healthy sun exposure for most people?
- 15-20 minutes per day on most days if possible. Naturally, use your discretion; if you have lilly-white skin and visit a tropical climate on vacation, 20 minutes at noon may be too much; if you are Latino or Black and live in Anchorage, 20 minutes may not be enough.
- As much skin area exposure as possible for a given temperature; facial exposure works helps with serotonin production and SAD through your eyes, but not much with vitamin D. Your face only has about 7% of your total skin area, so it is not very effective for vitamin D production.
- Infants should get less sun because their skin is not yet full developed and is of course lily-white from the womb, but by 6 months old a limited amount of sun is helpful even for small children.
- If you have a medical condition or are taking medication that is contraindicated with sun exposure, please see your physician before getting sun on your body.