Monthly Archives: February 2007

The Vitamin D Story. An Old Dog with Some New Tricks.


Mention Vitamin D to most people and they will try not to yawn. One of the less glamorous vitamins it is known as the sunshine vitamin because our skin, when exposed to the ultraviolet rays in sunlight, manufactures vitamin D. Not unexpectedly sunscreen on the skin blocks this production. The remainder of our body’s supply of this vital vitamin comes from a limited number of foods. The main role of vitamin D is thought to promote intestinal absorption of calcium. Calcium is crucial for bone development. Children without enough vitamin D suffer from a disorder of abnormally soft bones known as rickets resulting in extreme bowing of the legs and dental problems. Adults with vitamin D deficiency can develop low blood calcium levels, osteoporosis, as well as softening of the bone known as osteomalacia.

Recent studies however, have shown that Vitamin D may serve many other important functions in the body. Several investigators found that low Vitamin D plays a role in “seasonal affective disorder” which is a form of depression occurring during the winter when little sunlight is available. Low levels of Vitamin D can be found in Alzheimer’s patients, and some researchers believe low levels of this vitamin may contribute to loss of muscle tone and frequent falling in the elderly. Recent studies link low Vitamin D levels in pregnant women to the development of preeclampsia (toxemia of pregnancy). Vitamin D was also shown to help lung function and to delay a common but serious eye disorder known as macular degeneration.

Studies also show that Vitamin D may help benefit the immune system and help reduce the incidence of certain cancers. Recent studies suggest vitamin D may help prevent or delay colon, breast and ovarian cancer. One study showed that 1000 IU of vitamin daily could cut the risk of colon cancer by 50% while another study found a similar risk reduction for pancreatic cancer in those who took vitamin D supplementation. Results of these studies are still inconclusive and require verification but point to an important role of vitamin D in cancer protection.

Until recently the recommended daily allowance of Vitamin D was 400 IU. Some researchers now state that this amount is too low and advocate a daily intake of 1000 IU. Vitamin D can be found in Vitamin D supplemented milk, many multivitamins and calcium supplements. Yoghurt, margarine, cooking oils, breakfast cereal and bread may also be fortified with vitamin D. Oily types of fish such as salmon, tuna, and sardines are excellent sources of vitamin D. In particular the fish liver stores much of the vitamin, hence “cod liver oil” is an excellent vitamin D source.

The vitamin D we ingest in pills and food is an inactive form of the vitamin which then must be activated in the kidney. For this reason those with kidney disease frequently must receive medication with activated vitamin D to prevent bone disease or other conditions related to low calcium levels in the blood.

A note of caution about vitamin D is sounded by some experts. While there is still plenty of debate about the amount of vitamin D which could be toxic, most authorities believe that up to 2000IU daily should be safe.

Only you and your doctor can decide on what medical treatments are best for you. The articles on metabolism.com such as this one are meant for educational purposes only and should not be used to guide you in your medical care. Speak to your health professional before undertaking to change or initiate medical treatment plans.

Gary Pepper M.D.
Editor-in-Chief
Metabolism.com

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Xenical for Weight Loss. Beware What You Wish For.


The FDA recently approved the weight loss medication Xenical (orlistat) for over the counter sales. Xenical has been available by prescription for several years and has been used by doctors in the United States to aid in weight loss programs. This medication works by blocking the intestinal absorption of the fat (triglycerides) in food. If fat is not absorbed in the intestine it passes right out of the body in the stool. Since fat contains about twice the number of calories per portion as protein and carbohydrate, by using Xenical every day a person can expect to lose a substantial number of consumed calories, initially losing weight at up to a pound or two per week. Studies of long term use of Xenical show that in those who can tolerate Xenical for a year, total weight loss is more likely to be in the range of about 5 to 10 pounds above that seen on diet alone.

What’s the downside of Xenical, you may wonder? Do you recall a few years back when a major company tried to market potato chips with a new kind of indigestible fat known as Olestra? The idea was that you could eat these potato chips guilt free because all the fat calories you get with regular chips pass right through you without being absorbed. This is the same principal as using Xenical then eating those regular potato chips. Why hasn’t this great idea worked out? Was it the taste, cost or texture of the product? No. It was the nasty side-effects of having all that undigested fat hit your colon. Soon after eating Olestra potato chips, diarrhea and “anal seepage” are the flip side of guilt free eating. Anal seepage occurs when liquid fat just runs out of your backside without your ability to stop it, except in your underwear. Try to image a vegetable oil enema.

Scientific studies show that using Xenical can help lower weight and cholesterol levels. In our opinion, these types of studies demonstrate just how unrealistic scientific studies can be. In clinical practice some doctors report the success rate of using Xenical may be as low as 1 in 5 people. These physicians will tell you that almost everyone who tries it, even with careful counseling about the best ways to avoid the embarrassing side-effects, finds it difficult to tolerate this medicine. We can only image the chaos about to occur in offices, buses, subways, airplanes, theaters around the country when undigested fat begins to hit the colon of first time Xenical users. We warn you not to stand in the way of these people as they head to the toilet!

Other considerations for those who use Xenical is that it can cause deficiency of certain vitamins, particular vitamins A, D, E and K. Taking a multivitamin several hours separated from Xenical has been recommended for this reason. This weight loss drug may interfer with the absorption of certain medications like thyroid hormone and cannot be used by individuals with a variety of bowel or liver diseases.

With these cautions in mind we at metabolism.com wait to hear from our members about their thoughts and possibly even their personal experiences using Xenical or Olestra containing products. All we can say about the prospect of a country about to experiment with Xenical is….Wowza!

Only you and your own doctor can decide what is the best treatment for you. The comments made here by the staff at metabolism.com are purely for educational purposes and are not meant to guide you in the treatment of any condition or illness.

Gary Pepper, M.D., FACP
Editor-in-Chief

http://www.metabolism.com

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Welcome to the blog @ metabolism.com


Metabolism.com is pleased to offer our members the opportunity to participate in this new blog.

Our mission is to share with you our expertise on a wide range of problems related to metabolism, nutritional health, weight control, as well as conditions such as diabetes, thyroid disorders, high blood pressure, cholesterol management etc. More than that, this blog enables our members to share their experiences and opinions with the staff and other readers.

One of the most common complaints we hear about is not being able to lose weight. In my practice of endocrinology every day I hear from many people about this particular problem. The solution is never easy. Consider the obvious fact that people must eat or die. The drive to eat is a primal instinct that drove our ancestors to brave the most dangerous and painful conditions in order to survive. It is remarkable to me that people can achieve any degree of sustained weight loss in the face of these natural inclinations.

In this blog we hope to join you in your efforts to achieve your health goals. We hope to hear from you with your own experiences and advice, as well as to give you the opportunity to interact with our staff.

Welcome to the blog at metabolism.com.

Gary Pepper, M.D.
Director, Metabolism.com

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