Vitamins: Too much or Too Little?
28 May 2007
"Do you want Ford or Cadillac vitamins?", I asked readers in a previous column. It triggered many requests, revealing much confusion about vitamins. Some readers had stopped taking vitamin E due to scary headlines. Others had tossed out calcium as being ineffective. Still others wondered if it’s possible to get too much of a good thing, and where to obtain more information on vitamins.
An excess of anything can be poison to the human body. Too much vitamin A can cause fetal defects in pregnant women and in others, severe liver damage. Hunters who eat bear’s liver which contains large amounts of vitamin A have suffered from liver failure. We need no more than 10,000 IU of A daily.
You can also get too much of iron. Research shows one person in 250 has an inherited disorder, hemochromatosis, in which iron accumulates in body organs and eventually destroys them.
A study of 1,300 men who took 200 micrograms (mcg) of selenium daily for four and a half years had a 75 percent less chance of prostate cancer and half the risk of colon malignancy. But taking 800 mcg daily can make the nails or hair brittle. Or hair may fall out. Moderation is usually the best course.
But rather than worrying about getting too many vitamins and minerals most people should be concerned about being deficient in them.
For example, vegetarians who do not eat meat or dairy products can be lacking in vitamin B-12. So can those older than 50 who may have insufficient stomach acid to absorb this vitamin. These groups need 25 mcg of vitamin B-12 daily. Others taking stomach acid blockers may need 250 to 500 mcg daily. A deficiency of B-12 can cause irreversible nerve damage and masquerade as Alzheimer’s disease.
Don’t place too much faith in one study that recently hit the headlines. For years it was believed that vitamin E was cardio-protective. Then it was reported that E did not prevent cardiac problems and increased the risk of dying. But further studies show it’s an excellent antioxidant and helps to fight several degenerative diseases such as cataracts. I believe it’s still prudent to take this vitamin.
This year a study of 36,000 postmenopausal women revealed that calcium along with vitamin D (which helps to absorb calcium) failed to decrease the risk of bone fracture. But other researchers have shown that increased calcium results in a significant reduction in hip fractures. Besides, calcium has other important functions.
Calcium along with magnesium and potassium help to decrease blood pressure. Most people are not getting sufficient amounts of these minerals. So rather than being concerned about calcium, people should worry about the huge amount of salt consumed each day which contributes to hypertension. It also increases the rate of excretion of calcium in the urine which may have an adverse effect on osteoporosis.
So what is a Cadillac vitamin? Seven renowned researchers graded hundreds of vitamin products to determine whether they contained all the ingredients needed for optimum health. For instance, we know that optimum health requires 22 different minerals. Minerals we need in tiny amounts are called trace minerals such as selenium, copper, zinc manganese and chromium. These minerals are just as important to health as the major ones.
Some products I had been taking did not score well which triggered the previous column. And being a Scot I wanted to get value for my money.
If you want to explore this matter further there is an excellent book "Nutritional Supplements" that grades over 1,500 Canadian and U.S. supplements and lists top-rated products.
It’s packed with information about oxidative stress, inflammation and a good source for those who are interested in optimal nutrition. See the web site www.comparativeguide.com. Nutritional Supplements also lists web sites such as www.vrp.com and others where quality vitamins can be obtained.
The prime message is not to either under dose or over dose with vitamins. Nor can vitamins undo a lifetime of faulty habits.
So Rule # 1 is always to follow a good lifestyle starting early in life. And Rule #2 is never to forget Rule # 1.
