- If your shadow is taller than you, you can’t make Vitamin D; when your shadow is taller than you, the angle of the sun is such that UV B rays are blocked. UV B rays are what we need to synthesize Vitamin D.
- In the Pacific Northwest, we have a “Vitamin D deficient winter” which means that we cannot synthesize Vitamin D during the winter due to the position of the sun.
- On average, it takes 10-15 minutes to synthesize a day's worth of Vitamin D.
- Dark‐skinned individuals often require up to 30 minutes or more of sun exposure to synthesize enough Vitamin D.
- The EPA and Coppertone have some free apps that let you measure the UV index on a daily basis. These apps help you determine how long to stay in the sun, and when to reapply sunscreen.
- The sun is strongest between 10:00 am – 4:00 pm.
- You can still get sunburned on cloudy days – cloud cover only reduces sun exposure by 50%.
- Dogs are also susceptible to sunburn, especially on their nose and belly. Use canine sunscreen, or regular sunscreen without zinc oxide.
- Fatty fish such as salmon and swordfish are excellent sources of Vitamin D.
Vitamin D Facts from the Office of Dietary Supplements, National Institutes of Health
Vitamin D information from the Micronutrient Information Center at the Linus Pauling Institute (also available in Spanish).
How do I check my skin? (includes a Body Mole Map) from the American Academy of Dermatology
Skin Cancer and Skin Color information from the Skin Cancer Foundation