Vitamin D is not actually a vitamin but a hormone: A chemical substance produced in the body that controls and regulates the activity of cells and organs. Vitamin D is naturally created in adequate quantities by almost all mammals when exposed to sunlight. In contrast, vitamins are organic compounds that cannot be created in sufficient quantities by the organism itself, and must be obtained from outside sources in the diet.
The “sunshine vitamin” got its name because large quantities of vitamin D are made in the skin when exposed to sunshine. A very small section of the ultraviolet range of sunlight called UVB is responsible for all vitamin D synthesis in the skin. During sun exposure, a natural chemical in the body (called 7-dehydrocholesterol) is converted to vitamin D3 in the upper layers of the skin.



Nature has created a perfect time-release system for vitamin D: The vitamin D made during a single exposure to the sun is delivered to the bloodstream over a two-week period. It is a very efficient system that research has shown generates over 90% of all vitamin D in our body. Nature also instilled in us an unconscious desire to go in the sun for proper health. Endorphins are made in the skin alongside vitamin D, making us feel good and reinforcing this beneficial behavior.



Nature provided two forms of regulation to this system to prevent overexposure and overproduction: The skin has the ability to create a suntan that works as a natural SPF to prevent overexposure (sunburn) and slow vitamin D photosynthesis during intense UV exposure. In addition, the skin has a natural feedback system, called photo-degradation, which destroys excess vitamin D in the skin after higher levels have been attained. As with any hormone, endogenous regulation is critical for your body to function properly.



It is estimated that 3% of the human genome is regulated by vitamin D. Like many hormones, it has profound effects on systemic health and wellness. Vitamin D receptors are located in all the organs and nearly every tissue in the human body. Aside from regulating calcium metabolism for proper bone health, this hormone has been shown to positively impact soft tissue metabolism as well. The abundance of receptors throughout the human body illustrates the impact that vitamin D has on innumerable aspects of our health and function.


"Nature does nothing uselessly" - Aristotle



Vitamin D deficiency occurs at blood levels < 20ng/ml, the minimum level required for proper bone health. Insufficiency (hypovitaminosis D) is defined as blood level < 30ng/ml, the minimum required for soft tissue metabolism health. Scientists believe optimum levels are probably closer to 60ng/ml. Studies indicate hypovitaminosis D is an epidemic, with greater than ¾ of the population presenting insufficient levels of this essential hormone. Why do we have this epidemic?