Saturday, September 5, 2009

Vitamin E suppliments are used by the body

One of the most despicable comments I hear is "vitamin supplements give you expensive urine." This is totally untrue and yet is made by people who appear knowledgeable on the subject. Thus some people believe that they shouldn't be supplementing as it does no good.

There is no scientific basis for the comment that vitamin supplements are not absorbed or used by the body. It is based upon the urine color, which is just one vitamin, vitamin B2 /riboflavin. This vitamin is water soluble, and there are no body stores. Thus the body takes all it needs and removes the rest.

Thus when I read a study that has measured vitamin or mineral levels increasing in tissues as response to supplementation, it is yet another nail in the coffin about how supplements are a waste of time. Today's post is about how vitamin E is taken up into selected body tissues.

In the early 90's a study was undertaken investigating dogs and vitamin E deficiency. It was found that dog's are a much better model of human vitamin E deficiency than rats, which had bee used up till this time. They study also looked at supplementing vitamin E to dog's above the dogs standard laboratory diet.

Now the standard laboratory diet for dogs is 74IU/kg of feed. The high vitamin E diet was 114IU/kg of feed. This increase in feed corresponds to a 150% increase in vitamin E intake.

It is estimated that a person in the Western world has approximately 2kg of food a day, so adult RDI is approximately 10IU/kg food intake. In terms of specific vitamin E supplementation a 200IU supplement would be on the low side, and 400IU on the high side, (typically multivitamins have around 22.5IU as this is the RDI.) So with vitamin E supplements would be at 100 - 200 IU per kg of food.

Now vitamin E deficiency, which may take decades to occur in humans, is associated with nerve damage such as shaking, loss motor control etc. Therefore this study looked at vitamin E levels in the nerve areas. (Part of the study was looking at dogs on vitamin E deficiency diet, but this does not concern us). The results are shown below (click on the graph to make it bigger), it is the percentage of increase (or decrease) from the normal to higher vitamin E diet. A result of 100%, would mean that there was no increase from the normal to the higher diet. 200% would indicate that the higher diet resulted in twice the vitamin E level and so on.

What is fascinating is that the higher vitamin E diet was 150% of that lower diet, yet all the nerve systems increased by at least 200%, that is twice the level, and the highest difference was 5 times the level. This means that the brain and the nerve systems are proactively taking up vitamin E. If it was a passive uptake we would expect to only see a rise of 150%. The same can be said of muscle and heart tissues.

What is equally fascinating is that there was a drop in fat tissue (adipose tissue) and liver levels. This is fascinating as vitamin E is a fat soluble vitamin, thus the vitamin E in the body fat stores would be expected to rise. The liver is thought to store "excess" vitamin E so the body can use it if it needs to. However this result would indicate that liver does not store vitamin E, or that it stores a small amount, that that increasing vitamin E intake, does not increase storage, but increases the amount used by the body.

The adrenal gland and kidneys level increased by approximate 150% (162% and 179%). This indicates these organs passively increase their vitamin E level, that is not actively like the nerve system above. Thus adding more weight to the hypothesis that vitamin E was being actively pumped into the nervous tissues.

Now as dogs are seen as a better model than humans, it is surprising that the standard dose of vitamin E of 74IU/kg of feed is much higher than the standard human dose of 10IU/kg of food. The difference is even larger when the dogs are feed the 114 kg/IU dose. This would imply that if you take a vitamin E supplement you will obtain a significant increase in the vitamin E levels in your muscles, brains and nerve system.

S hreekumar R. Pillai, Maret G. Traber, Janet E. Steiss, Herbert J. Kayden and Nancy R. Cox α-tocopherol concentrations of the nervous system and selected tissues of adult dogs fed three levels of vitamin E. Lipids. Volume 28, Number 12 / December, 1993, link

Shreekumar R. Pillai, Maret G. Traber, Janet E. Steiss and Herbert J. Kayden Depletion of adipose tissue and peripheral nerve α-tocopherol in adult dogs. Lipids. Volume 28, Number 12 / December, 1993 link

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