Vitamin D is important in many aspects of our health from healthy bones to protection from cancer, and other diseases such as heart disease, and autoimmune disease. Although it is known as the “Sunshine Vitamin” you are not always getting Vitamin D when the sun is shining. In fact it is estimated that 50% of the population in North America are Vitamin D deficient. Our mechanism for making Vitamin D depends on the availability of UVB rays. Anyone above latitudes of 37° north of the equator, which is about the Colorado/New Mexico border, and below latitudes of 37° south of the equator experience what is known as “Vitamin D Winter”, where no UVB rays can penetrate the ozone. In Colorado this occurs during the months of November through March and shuts down our ability to make our own Vitamin D.
What you need to know:
Your body is designed to make its own Vitamin D with exposure to the UVB rays of the sun.
Just 10-15 minutes of sun exposure depending on your skin color (chest, arms, legs, torso- think 40% of your body) between 10 AM-2 PM will give you 10,000 IUs of Vitamin D.
When your skin is pink to the touch, you’ve made 10,000 IUs of Vitamin D, do not overexpose.
Keep in mind sunscreen with as little as SPF 8 can block your Vitamin D production by 100%.
Burning leads to skin cancer so be mindful of your time in the sun and when you do apply sunscreen be sure to refer to EWG’s sunscreen guide for the latest research and recommendations of the safest sunscreens available.
Vitamin D Supplementation
There are many factors that affect vitamin D levels such as the season, time of day, and skin color so it is important to monitor your blood levels while supplementing.
Vitamin D is fat soluble and is best absorbed in liquid form not through pills.
It is essential to supplement and eat foods high in Vitamin D throughout the winter when your body is not able to make its own from the sun. Here in Denver that is November through March.
Vitamin D food sources
Wild caught salmon
Eggs
Mushrooms
Sardines
Halibut liver oil
Wild caught mackerel
Sources:
http://www.health.harvard.edu/newsweek/time-for-more-vitamin-d.htm