Four years ago, I became convinced that vitamin D was unique in the vitamin world by virtue of three facts. First, it’s the only known precursor of a potent steroid hormone, calcitriol, or activated vitamin D. Most other vitamins are antioxidants or co-factors in enzyme reactions. Activated vitamin D – like all steroid hormones – damasks the genome, turning protein production on and off, as your body requires. That is, vitamin D regulates genetic expression in hundreds of tissues throughout your body. This means it has as many potential mechanisms of action as genes it damasks.
Second, vitamin D does not exist in appreciable quantities in normal human diets. True, you can get several thousand units in a day if you feast on sardines for breakfast, herring for lunch and salmon for dinner. The only people who ever regularly consumed that much fish are peoples, like the Inuit, who live at the extremes of latitude. The milk Americans depend on for their vitamin D contains no naturally occurring vitamin D; instead, the U.S. government requires fortified milk to be supplemented with vitamin D, but only with what we now know to be a paltry 100 units per eight-ounce glass.
The vitamin D steroid hormone system has always had its origins in the skin, not in the mouth. Until quite recently, when dermatologists and governments began warning us about the dangers of sunlight, humans made enormous quantities of vitamin D where humans have always made it, where naked skin meets the ultraviolet B radiation of sunlight. We just cannot get adequate amounts of vitamin D from our diet. If we don’t expose ourselves to ultraviolet light, we must get vitamin D from dietary supplements.
The third way vitamin D is different from other vitamins is the dramatic difference between natural vitamin D nutrition and the modern one. Today, most humans only make about a thousand units of vitamin D a day from sun exposure; many people, such as the elderly or African Americans, make much less than that. How much did humans normally make? A single, twenty-minute, full body exposure to summer sun will trigger the delivery of 20,000 units of vitamin D into the circulation of most people within 48 hours. Twenty thousand units, that’s the single most important fact about vitamin D. Compare that to the 100 units you get from a glass of milk, or the several hundred daily units the U.S. government recommend as “Adequate Intake.” It’s what we call an “order of magnitude” difference.
Source/Full Story:: medicalnewstoday.com
One Comment
Agree, everyone should know about vitamin D deficiency it is a pandemic as our jobs and life style keep us indoors. Take a look at http://www.vitaminD3world.com for some good summaries of the data. The site also has a good newsletter