Vitamin D3 is one of the winners among vitamins. It is a winner in that so many of its benefits are now coming to light and its star is definitely rising. In terms of disease prevention and recovery, it is a powerhouse.
Yet vitamin D3 still gets no respect, but it should. We can’t say it enough; this may be the most vital of all the vitamins for maintaining health. All the vitamins are necessary and important but D3 is exceptional.
Officially we need something like 400 mg/day which is just enough to prevent a deficiency. Most cases of vitamin D deficiency appear in children in developing countries and are characterized by the softening of the bones associated with deformities.
Rickets is the name commonly given to a D3 deficiency or we may see the name osteomalacia used to describe the condition. The same condition can also be caused by a deficiency of calcium or phosphorus.
There are numerous reasons why someone may develop a vitamin D deficiency but poor nutrition and inadequate exposure to sunlight top the list. Commercially processed milk is almost always fortified with vitamin D as is most breakfast cereals. For this reason, vitamin D deficiencies in children are actually quite rare in the U.S.
There are some prescription drugs that can destroy vitamin D; epilepsy drugs to control seizure is a good example. The worldwide obesity epidemic also contributes to a fall in vitamin D levels in people. That is because obesity keeps vitamin D stored in fat and keeps it from circulating in the blood.
Then there is the example of the blond starlet who stayed out of the sun, never went out without sunscreen and didn’t like milk then wondered why her bones were soft and painful.
How Much is Enough?
Recommended Dietary Allowances (RDAs) set by the government are “the average daily levels of intake sufficient to meet the nutrient requirements of nearly all healthy people”.
For vitamin D, they are the same for both sexes and vary only by age. At the low end is 400 IUs (10 mcg) for infants up to one year of age. Then it jumps to 600 IUs (15 mcg)from one year to age 70 and peaks at 800 IU for individuals over 70.
There are many nutritional experts who see a rising epidemic in vitamin D deficiencies and maintain that the reason is due to the government setting the RDA too low. Depending on what articles you read by these experts, the requirements should be anywhere from 2000 IUs to 4000 IUs per day and food should be much more heavily fortified.
Form and Function
There is not just one vitamin D. There are several forms of vitamin D and the form and function matters.
The two forms typically found in vitamin supplements are Vitamin D2, called Ergocalciferol, and vitamin D3 called Cholecalciferol. The first is plant-based and, among other things, is found in mushrooms; the second is obtained from animal-based foods.
The natural source of vitamin D is good old sunshine. When the sun’s ultraviolet-B rays strike the skin, they penetrate to the skin’s subcutaneous layers and make a version of D3 from cholesterol. This “previtamin D3” as it is called, is sent to the liver and then to the kidneys for final activation into D3.
According to Dr. Michael Holick, Ph.D., M.D., exposure to sunlight that turns the skin red can be equivalent to a dose of 20,000 IUs. Dr. Holick is sometimes referred to as Dr. Sunshine for his extensive research into vitamin D.
By the way, the toxicity of D is in its fully activated form and we need a fully functional liver and kidney to get to that form.
The Vitamin D3 Breakthrough
The big breakthrough in vitamin D3 is in the sheer breadth of health benefits it bestows. The fact that it helps in the absorption of calcium and phosphorus has been known for a long time. Also, its role in regulating cells and blood calcium has been well known. In its regulatory role, vitamin D has been likened more to a hormone than a vitamin.
Now comes the breakthroughs. It turns out that vitamin D3 is needed for insulin production in the pancreas and may lead to new treatments for type 1 diabetes. The normal function of beta cells that produce insulin need vitamin. The notion that a vitamin could be prevention for diabetes is huge.
MS, multiple sclerosis, is a horrible disease in which the body attacks the myelin sheath surrounding neurons of the central nervous system. It has been noted that the farther away from the equator one lives, the more likely they are to develop MS.
According to a study reported in the Journal of the AMA, if you lived above 35 degrees latitude for 10 years as a child, your risk of developing MS as an adult increases by 100%, that is it doubles.
Cancer prevention may be a vitamin breakthrough of all time. It appears that vitamin D protects cells from cancer.
Toxicity and Contraindications
The knee-jerk reaction of too many healthcare professionals is that we shouldn’t take more than the RDA of vitamin D, it is too toxic. Well no it’s not and 20,000 IUs a day is still safe.
The belief probably comes from the fact that it is fat-soluble and excesses do not get excreted in the urine, it is stored in fat. Toxicity is a minimal concern since there are plenty of health challenges in all of us that the D3 is put to good use.
Vitamin D is only toxic in its fully activated form of D3 and we need a fully functional liver and kidney to get to that form. It is not unusual for a doctor to prescribe up to 50,000 IUs in a single once-a-month dose to correct a deficiency.
Furthermore, the production of vitamin D3 from exposure to the sun is not toxic since skin can down-regulate the D3 precursor (previtamin) that is sent to the liver so it is possible for us to put the brakes on skin, liver or kidney function in the chain of events.
Supplements can be toxic but you can’t buy enough fully activated D over the counter to reach that point. Most D3 toxicity seen is from the prescription doses mentioned above, not supplements.
If you take time to watch the embedded video, toward the end we see that there are two contraindications to be aware of. The first is that vitamin A and vitamin D share the same receptors so vitamin A levels should be kept below 6000 IU/day.
1000 IU/day of vitamin A should be enough. The RDA for vitamin A from the NIH’s ODS is 1000 IU/day for kids and up to 3000 IU/day for adult males.
The second in that granulomatous diseases (hereditary immune disorder), TB and sarcoidosis (chronic inflammation of the lymph nodes and various organs)may cause the serum 25(OH)D to run high, thus becoming hypercalcemic.
The 25(OH)D is shorthand for the 25-hydroxy vitamin D test that tells how much vitamin D is in the body. It is a simple blood test and gives the most accurate reading available.
Before starting vitamin D3 supplementation it is highly recommended to get the test done to establish a baseline and then test in March and again in August or September. March is when vitamin D levels are lowest and late summer they are at their highest.
Supplementation and periodic testing should be done with the objective of keeping vitamin D blood levels between 40 and 60 ng/ml.
The Last Word
The last point is that food is not typically a natural source of vitamin D for human beings; the sun is. To bring home the point, we would have to drink 5 quarts of milk a day or eat five servings of oily fish a day to reach the recommended levels.
When it comes to vitamin D3…Supplement!