Gettysburg Medical News
The Clinical View
by P.E. Hoffsten, MD
13 February 2008

NOW YOU NEED 2000 UNITS A DAY OF VITAMIN D3

            I last wrote about the problem of Vitamin D deficiency in the column on June 29, 2006. Since then, there have been a host of new studies and new information released.  Previously, it was said by the FDA that the adult minimum daily requirement for Vitamin D was 400 units.  In the column in June of 2006, I said that should go to 1,000 units per day.  Now for a host of reasons, the right dose is 2,000 units of Vitamin D3 per day. 

            The Vitamin D effect was originally described 185 years ago by physicians in Europe.  There the industrial revolution was causing more people to work inside with less exposure to the sun.  The bone disease caused by vitamin D deficiency called rickets was epidemic.  Rickets is a disease in which the normal mineralization of bone just does not occur.  Thus, children working factories and not exposed to the sun develop bowed legs and easy fractures.  In 182, physicians in Poland noted that children still working the fields and exposed to the sun had a much less incidence of rickets.  Two years later, German scientists found that a cure for rickets could be obtained by a tablespoon a day of cod liver oil.  As horrible as it tasted that was still used until the 1950’s.

            Surprisingly, another vitamin D effect was observed in the early part of the last century when it was recommended that tuberculosis patients go to Arizona to be cured of their tuberculosis.  It worked surprisingly well.  While many people thought that the effectiveness was the rest and tranquility, the real answer was the extra does of sunshine that they received in Arizona that enhanced their vitamin D production.  It turned out that Vitamin D is a potent immuno-protector.  By supplementing vitamin D, tuberculosis patients were able to cure themselves.

            By 1922 vitamin D3 had been isolated and identified as the active ingredient in cod liver oil.  But it took another 50 years to fully unravel the very complicated metabolism of vitamin D.

It turns out that a breakdown product of cholesterol called “7,dehydrocholesterol” is converted to vitamin D3 by sunlight on the skin.  Vitamin D3 is taken to the liver where it was converted to a product called “25,hydroxy vitamin D3” which was then carried to the kidney and made into “1,25dihydroxy vitamin D3” which is the active ingredient of vitamin D.  Thus in order to produce enough vitamin D, a person needs to have both effective liver function and effective kidney function.  Those individuals with chronic kidney failure need an extra supplement of a special form of Vitamin D in order to maintain their bone mineral integrity. 

            More recent findings have overshadowed this very complicated chemical story of how vitamin D is made in our bodies.  It turns out now that vitamin D is an anti-cancer drug.  By the 1980’s, it was apparent that there was a relation between exposure to the sun and a decreased incidence of certain types of cancer.  Extensive subsequent research working in animals have demonstrated very clearly that vitamin D will both decrease the incidence of cancers and slow the growth of those that are present. 

            Lastly, in a very striking series of studies in the last 20 years, it has been shown that there is a relationship between vitamin D deficiency and multiple sclerosis.  It has been known for many years that the northern latitudes away from the equator have a much increased incidence of multiple sclerosis compared to individuals living closer to the equator.  That link was eventually traced to Vitamin D.  The study involved seven million army and navy personnel to see which individuals in this young age group would develop multiple sclerosis in their future.  The study was conducted between 1992 and 2004.  There was a definite decreased risk of developing multiple sclerosis in a group with high Vitamin D3 levels.  Simply by correlating vitamin D blood levels in samples taken at the time of induction into the armed services, it was shown that there was 62% reduction in the incidence of multiple sclerosis in those recruits with higher levels of vitamin D. 

            So what is the right dose of vitamin D and what are the dangers of supplementing it?  In the past, it was thought more than 1,000 units a day might be associated with an increased incidence of kidney stones.  That has not turned out to be the case.  The real dose of Vitamin D3 in today’s population should be 2,000 units per day.  This is a very cheap product bought over the counter at any pharmacy.  In our age of using carbonated beverages instead of milk and decreasing exposure to sunlight, vitamin D supplementation becomes a critical part of our long term health. 

            As a last point to make, it turns out that vitamin D is also a blood pressure protector.  Pharmacologic doses of vitamin D such as 2,000 units per day tone down the renin-angiotensin system that causes hypertension.

            Thus, in summary, vitamin D is a critical element in our diets.  It protects:

            1.  bone health

            2.  by cancer prevention

            3.  as an antihypertensive

            4.  as an immune stimulant

            5.  and as a vitamin previously shown to stimulate muscle strength and decrease the
                 incidence of falls especially in the elderly.

I can’t think of any product in our civilization that costs less and does more with no downside.  The right dose is 2,000 units of vitamin D per day.

This and other columns available at www.macpierre.com.