A few yers ago I found out that my Vitamin D levels were extremely low, so of course my doctor put me on a high dose of Vitamin D to increase my levels. Within a day or two of being on the vitamin D therapy I began to notice an increase in my energy. I began sleeping better and my mood had improved tremendously – I felt myself coming up out of a fog of depression. When I expressed my excitement over this improvement, one of the comments I received was, “What the hell! It’s just a vitamin right? And with that, I set out to find exactly what this seemingly miracle vitamin was actually about.
Vitamin D is not really a vitamin at all - it is a pre-hormone that's produced in your skin in response to sunlight exposure. As such, it is an integral part of human health and longevity. It is critically important for the development, growth, and maintenance of a healthy body, during the entire life cycle. There are several forms of vitamin D: supplemental vitamin D, pharmaceutical vitamin D, and those that exist in the body called vitamin D's metabolites.
Supplemental Vitamin D comes in two forms, Vitamin D3 and Vitamin D2. Vitamin D3 is labeled as the “real” Vitamin D as it is the form produced in human skin in response to sun exposure. It can be derived from either lanolin or cod liver oil and according to the Vitamin D Council, it is the only form that should be used to treat Vitamin D deficiency. Vitamin D2 is derived from fungal sources and is not naturally present in the human body and may have actions within the body different from those of vitamin D3, however many doctors still prescribe vitamin D2.
After vitamin D is formed in the skin, it is metabolized into two different substances within the body: 25-hydroxyvitamin D, or calcidiol, and 1,25-dihydroxyvitamin D, or calcitriol. Calcidiol is made in the liver and it is a prehormone and the body's main storage form of vitamin D. Calcitriol is made in the kidneys as well as in other organs, and is the most potent steroid hormone in the human body. It is said by the experts to “unlock” a cell’s DNA library.
The human body was designed to receive vitamin D by producing it in response to sunlight exposure, therefore this should be the method of choice. Over exposure is not necessary since Vitamin D is produced within minutes – in about half the time it takes for the skin to begin changing color, all of the Vitamin D the body will make for the day is produced. For vitamin D production, sun exposure should be during midday between the hours of approximately 10am-2pm. These hours will vary depending on latitude but the closer to solar noon, the more vitamin D produced.
Vitamin D production occurs faster in those with light skin than in those with dark skin. This is because darker skin has higher melanin content. Melanin is Nature's built-in protection against skin damage from excess ultraviolet exposure and so it allows less UV to enter the skin. This is why those whose ancestry is native to regions near the equator have darker skin than those native to regions located at higher latitudes. It is also why those with darker skin living at higher latitudes have higher prevalence of vitamin D deficiency.
Food sources rich in Vitamin D include fatty fish eggs, red meat, and liver. However, a great vegan source is light-exposed (wild) mushrooms which can provide up to 100% of the recommended allowance of vitamin D.
Being “D-ficient” may increase the risk of chronic diseases, such as osteoporosis, heart disease, multiple sclerosis, and cancers such as breast, colon, ovarian, prostate and others, as well as infectious diseases, such as tuberculosis and the flu. In addition it helps to prevent type 2 diabetes, insulin resistance, and high blood pressure; it lowers the risk of excessive inflammation, supports mood stability and cognitive function. Vitamin D regulates insulin activity and blood sugar balance, regulates immune system response and helps prevent chronic fatigue – I could go on.
There seems to be some debate over what the optimum levels of Vitamin D are but the majority of researchers seem to agree that adequate levels are between 39 to 70 ng/mL and for those with health issues related to “D-ficiency” levels between 55 and 85 ng/mL may be necessary. Levels above 150 ng/mL are dangerously toxic. To find out if your levels are adequate or “D-ficient” and for proper treatment see your doctor.
My D levels eventually increased but I constantly remain on the low side of "normal", and often dropping below normal during the winter months. Unfortunately this is not uncommon for those of us who live in the states north of Florida. Therefore, Vitamin D therapy is an ongoing process for me.