About Vitamin D

Natural production of vitamin D occurs in the skin of all people everywhere when 7-dehydrocholesterol molecules in skin absorb ultraviolet-B (UVB) light, at the 290-315 nanometer long wavelengths, which is sometimes present in sunlight. The earth spins (one spin equals one day) and wobbles (one wobble equals one spring, summer, fall, and winter, one year) as it orbits the sun.  As a result, much of the time ultraviolet-B light is not in sunlight because the sun is either too low in the sky for vitamin D production (the ultraviolet-B light in sunlight is bouncing off the earth’s atmosphere) or the sun is not in the sky at all (it’s nighttime).

Once a day each day, when the sun is at its highest in the sky, 290-315nm UVB light from the sun may be reaching the surface of the earth during the middle hours of the day at where you are located on the earth’s surface and for longer amounts of mid-day time at locations closer to the equator (where the sun is even higher in the sky).   

The wobble of the earth tilts the earth. At the time of the year when the earth is tilting toward where you are on the surface of the earth, the days are long, the sun is high in the sky, and sunlight has 290-315nm UVB light in it during the mid-day hours of the day (it is the summer season). When the earth is tilting away from where you are, the opposite is true.  Where you are located, the time of the day, and the season of the year determine how much 290-315nm UVB light is available to you, therefore how much natural production of vitamin D can occur in your body.

Clouds, ozone, and pollution in the air absorb 290-315nm UVB light, taking it out of the air.  At your location, even though the time of day and the season may be right for mid-range 290-315nm UVB light, which should be in the sky and getting all the way down to the ground, it may not be there due the number of clouds and the amounts of ozone and pollution in the sky. And also, for vitamin D production to occur in skin, the sunlight must be shining directly on the skin, not blocked by glass, clothing, sun screen, dust in the air, or dirt-and-oil on skin. Once the UVB light in sunlight is in skin it is absorbed by 7-dehydrocholesterol molecules which are in the lowest two layers of the skin and which converts the 7-dehydrocholesterol to vitamin D (cholecalciferol) molecules. Darker skin color also blocks ultraviolet-B light from reaching deep into skin (darker blocks more).

Once shining on skin, mid-range UVB light immediately starts producing large amounts of vitamin D.  Whole-body exposure to ultraviolet-B bearing sunlight has been estimated to produce 30,000 IU (International Units; by weight, 400 IU of vitamin D equals 10 micrograms of vitamin D) within an hour of steady exposure to ultraviolet-B 290-315nm light in the skin of an average sized lighter-skinned person, when adding in estimates to attempt to account for the movement of the 7-dehydrocholesterol molecules within skin cells and estimates of how fast spontaneous (also called “thermal”) isomerization (the reshaping of the 7-dehydrocholesterol molecule into a vitamin D molecule) may be occurring. The body safely handles such large quantities of vitamin D in skin keeping it in the skin until vitamin D-binding protein (GC) from the liver is made available to pick the vitamin D up and carry it into circulation. In spite of the human body’s ability to produce large amounts of vitamin D rapidly, many variables reduce natural vitamin D production.  Because of these variables, including the locations where most people live today, and the many cultural restrictions/limits most people living today live by, most people are

vitamin D deficient.

Since the 1930’s in the Western world, and (almost certainly) in India, China, and Russia in the East, governments have been extracting lanolin from sheep’s wool, a rich source of 7-dehydrocholesterol. After irradiating the extracted 7-dehydrocholesterol with ultraviolet-B light, they have been using it to provide vitamin D to their populations. But this method of producing vitamin D proved unable to meet world demand by even before the start of the 21^st century. Since then, among concerned scientists and governments around the world, a search has been ongoing for years now for economical and practical new sources of vitamin D.

Even more recently 7-dehydrocholesterol or vitamin D itself has come to be extracted from a variety of natural sources (organic vitamin D). The world’s demand for vitamin D now far exceeds what can be obtained each year through washing, extracting, and irradiating lanolin from sheep’s wool. One method of producing vitamin D that has been developed that appears capable of producing a potentially limitless supply of vitamin D (organic vitamin D) is done by bioengineering the Saccharomyces cerevisiae yeast, which has been used in bread, wine, and chocolate production for hundreds of years.  Saccharomyces cerevisiae is now re-engineered for 7-dehydrocholesterol production, then exposed to the same ultraviolet-B light as skin is in the natural production of vitamin D, converting 7-dehydrocholesterol molecules in the Saccharomyces cerevisiae yeast to vitamin D. Rubbing this yeast production vitamin D into the skin allows the skin to absorb the vitamin D and it remains in skin (it is hydrophobic, “water fearing,” and blood has a saltwater base (what it fears)) until vitamin D-binding protein (GC) from the liver picks the vitamin D up and carries it into and through circulation.

In the 1980’s Western scientists learned how to synthesize vitamin D from scratch in the lab (synthetic vitamin D). It is also a method of producing vitamin D that is capable of producing a potentially limitless supply of vitamin D at very low cost. Probably about a half a dozen of the world’s largest organic chemical and/or pharmaceutical companies now routinely manufacture and sell synthetic vitamin D.

Light Emitting Diodes (LEDs) that emit 290-300nm light have started appearing in marketplaces around the world (in the United States, Japan, Germany, and South Korea in the West, and also, perhaps, in the Soviet Union and in China in the East). So far none of these 290-315nm range LED lamps has maintained any more than a temporary toehold in the marketplace before disappearing, perhaps due to concerns about possible premature skin aging, skin damage, and skin cancer from exposure to UVB light.

Whether vitamin D is produced naturally in skin, or is added to skin (organic vitamin D or synthetic vitamin D), once attached to GC protein (vitamin D-binding protein), vitamin D is free to move through the body. On passing back through the liver the vitamin D (also called cholecalciferol) is converted to

calcidiol (also called calcifediol, 25-hydroxycholecalciferol, 25-hydroxyvitamin D₃ or 25(OH)D₃). The conversion of vitamin D to calcidiol is mandatory.  It occurs in the liver when vitamin D molecules encounter the liver enzyme CYP2R1 in endoplasmic reticulum in the liver (also called “the principal vitamin D 25-hydroxylase”), or also when vitamin D molecules encounter the liver enzyme CYP27A1 in mitochondria in the liver (also called “another vitamin D 25-hydroxylase”). Clinical note about CYP2R1: low levels of CYP2R1 activity have been found after 24-hour fasting, in obesity, in type 1 and type 2 diabetes, and in the presence of glucocorticoids. As a result, serum (circulating) calcidiol (25(OH)D₃) should no longer be used as a measure of the supply of vitamin D in the body.

The next and final conversion of vitamin D is the conversion of vitamin D to its biologically active form, which takes place in the kidneys,

calcitriol (also called 1,25-dihydroxycholecalciferol and 1,25(OH)₂D₃). Very little 1,25(OH)₂D is ever seen in circulation, because it is put to work immediately when it is made by binding to and activating the vitamin D receptor in the nuclei of cells everywhere throughout the body (again, vitamin D receptors are located throughout the body) increasing the expression of hundreds of genes, in turn increasing blood calcium.

At this point in science today (2025) it is known that

Where there are large accumulations of calcium phosphates in open space, circulating macrophages combine and make themselves into multinucleated macrophages (Figure 4), to surround (using neoplastic, “new form” membrane), break up, dissolve, encapsulate, and transport away calcium phosphate masses throughout the body, another tool the body uses to thoroughly clean and clear open space areas in the body.

Figure 4: A multinucleated macrophage looking for some calcium phosphate to consume. Multinucleated macrophages that consume calcium phosphate are also called osteoclasts (“bone splitters”).

WorkoutD is a method of applying vitamin D powder directly to the skin to make vitamin D plentiful in the body. The powder is manufactured by Provitas, at www.Provitas.com (thank-you, Provitas). Once a day apply a gram (100,000 IU, a heaping quarter (¼) teaspoon) or 2 (or more) of the vitamin D powder directly to your skin. Rub it thoroughly into your skin. Expect the vitamin D powder you apply to continue to be absorbed all day.  Remember, when you are in sunlight rich in 290-315nm ultraviolet-B (UVB) light you are naturally making and safely handling large quantities of vitamin D.

WorkoutD with exercise extends open space calcium phosphate cleanup to every corner of the body. You will be helping multinucleated macrophages locate calcium phosphate masses throughout your body. Phosphatases and calcium-binding protein work locally w/cells, multinucleated macrophages work system-wide, w/circulation.

J. Dalen