Listen to this video in it's entirety. Dr. Mercola has uncovered shocking new information that's imperative for taking control of our health.

malignant melanoma has been increasing at an exponential rate in indoor workers since before 1940. the reason may be indoor exposure to uva radiation. unlike uvb, which is blocked by glass, uva can pass through windows.

uva can cause cancerous mutations, and can also break down vitamin d formed after outdoor uvb exposure. and vitamin d is a potent defense against melanoma -- melanoma cells convert it to calcitriol, which causes growth inhibition and apoptotic cell death in vitro and in vivo. new research shows that increased uva exposures and inadequately maintained cutaneous levels of vitamin d promote melanoma...

...it’s important to understand that vitamin d3 is an oil soluble steroid hormone. it’s formed when your skin is exposed to ultraviolet b (uvb) radiation from the sun (or a safe tanning bed). when uvb strikes the surface of your skin, your skin converts a cholesterol derivative into vitamin d3.  

however, the vitamin d3 that is formed on the surface of your skin does not immediately penetrate into your bloodstream. it actually needs to be absorbed from the surface of your skin into your bloodstream. 

the critical question then is: how long does it take the vitamin d3 to penetrate your skin and reach your bloodstream? 

if you’re thinking about an hour or two, like i did until recently, you’re wrong. because new evidence shows it takes up to 48 hours before you absorb the majority of the vitamin d that was generated by exposing your skin to the sun! ...

...as i said earlier, one of the precursors for vitamin d is cholesterol. so if you’re taking drugs statin drugs, or proton pump inhibitors like prilosec or prevocid, which are typically used to treat ulcer conditions, you’ll naturally lower your cholesterol levels.  

this in turn will decrease your body’s ability to manufacture vitamin d.  

this is yet another potential reason your vitamin d levels may be low, or why you may have trouble optimizing your vitamin d levels.