Do you remember when you were a kid, playing outside in the spring or summer and feeling a deep sense of happiness, strength and relaxation? It is likely you were feeling the effects of that penetrating nutrient Mother Nature was pouring down on you from the sun: vitamin D.
History Lesson 101: In 1919, vitamin D was mistakenly classified as a “vitamin” when Sir Edward Mellanby discovered that rickets was caused by a deficiency of this particular nutrient. It was thought to be of such importance that the nutrient was deemed a “vitamin.” Rickets was so rampant that many scientists were working to demonstrate the relationship of vitamin D and sunlight, and its antirachitic effects. In 1924, one group – Hess and Weinstock – went as far as stating, “Light equals vitamin D.” Finally, in the 1930s, scientists chemically classified vitamin D as a steroid.
Today, we know of receptor sites for this nutrient in intestinal, bone, liver, kidney, skin, muscle, heart, brain, reproductive and lung tissues, which, through an elaborate vitamin D endocrine system, provoke biological responses in more than 30 target tissues. It is not merely an aid to calcium in bone building, it is imperative for survival.
Scientists are now taking note that the majority of people living in North America have a vitamin D deficiency, which is associated with increased risk of osteoporosis, diabetes, high blood pressure, depression and cancer.
Why is there a deficiency? People have migrated away from the equator and live in latitudes with less UV exposure throughout the year, especially during the winter and spring seasons. Industrialization and urbanization brought us indoors. Pollution, cars and clothing have decreased the amount of time our bare skin encounters the light and heat of the sun’s rays, which, when they are absorbed by the skin, are converted in to the metabolically active form vitamin D3 (cholecalciferol). And we all know about the warnings from the medical community about the dangers of the slightest amount of sun exposure and the need for SPF 45.
Please, research vitamin D, Google it, do whatever you have to do to get more of it in you. Why do you think influenza kills more people during the winter months but disappears in the summer? Did you know that summer sunlight increases brain serotonin (a neurotransmitter that modu- lates mood) twice as much as winter sunlight? There is a wealth of information connecting vitamin D deficiency with diseases such as autism, chronic pain, autoimmune illness and multiple sclerosis. To learn more about vitamin D and its benefits check out the Vitamin D Council at www.vitamindcouncil.com.
Unfortunately, we’ll have to be patient while the scien- tists wrestle to determine the “official” recommended dosage of vitamin D. In the meantime, I do have some helpful bits of information. A 20-minute full-body Hippie Hollow exposure in the summer is enough for your body to make 20,000 IU, or international units, of vitamin D. (People with darker skin require more time to get the same dose.) Compare this with the recommended daily allowance of 200 IU per day, which appears to be insufficient and is, seemingly, causing a deficiency. That is not to say your oral daily dose should be 20,000 IU. Some scientists, however, are saying a person who completely avoids the sun needs about 4,000 IU a day. And, since you would need to drink about 40 glasses of milk to get this amount of vitamin D, you might consider supplementation. When searching for a supplement, purchase one that is a vitamin D3 (cholecalciferol), and remember that a sublingual preparation (taken under the tongue) will be most efficiently absorbed.
We are so fortunate to live in the great city of Austin, where the sun shines 300 days a year. So get out there and soak it up!
As a result of a vitamin D deficiency pandemic:
- Milk became fortified with vitamin D in 1931
- Doctors in Boston found that three out of five elderly hospitalized patients were vitamin D deficient in 1998
- A re-emergence of rickets in children caused the American Academy of Pediatrics to increase its vitamin D guidelines in 2003
- A group of 15 international researchers led by Reinhold Vieth published an urgent call for nutrition agencies to increase vitamin D intake requirements in 2007