The Importance of Vitamins in Our Diet

Tablets. (iStockphoto/Thinkstock)
Tablets. (iStockphoto/Thinkstock)

In general, most people know the importance of vitamins in our diet. But many people do not know which vitamins are really important in maintaining good health.

I would like to revisit an article I had discussed about ten years ago on this topic. Not much has changed since. The topic was also discussed in a Clinical Practice article in the New England Journal of Medicine (NEJM) titled, “What vitamins should I be taking, doctor?”

Medical teaching says that a healthy individual, who eats a good diet, does not require vitamin supplements. He should be able to meet his vitamin needs from his healthy diet. But the public interest in vitamin supplements is enormous – sometimes due to misguided reasons. Almost 30 percent of our population takes vitamin supplements. And there is no control over it.

Because the food we eat contains too many nutrients, it would be almost impossible to conduct double blind trials to see if vitamins do have improved clinical outcomes. Also the users of vitamin supplements may have healthier lifestyles or behaviours than nonusers. This would distort any clinical trial results.

The good thing about vitamin supplements is that there is greater likelihood of good than harm and cost of supplements is not that high so the authors of the article in the NEJM recommend the following vitamin supplements for healthy individuals. There is substantial evidence that higher intake of:
1. folic acid (400 ug/day),
2. vitamin B6 (2 mg/day),
3. vitamin B12 (6 ug/day), and
4. vitamin D (400 IU/day) will benefit many people, and a
5. a multivitamin will ensure an adequate intake of other vitamins for which the evidence of benefit is indirect.

The authors say a multivitamin is especially important:
-for women who might become pregnant
-for persons who regularly consume one or two alcoholic drinks per day
-for the elderly, who tend to absorb vitamin B12 poorly and are often deficient in vitamin D
-for vegetarians, who require supplemental vitamin B12 and
-for poor urban residents, who may be unable to afford adequate intakes of fruits and vegetables.

It should be noted that recent recommendation for vitamin D suggests all adults should take 1,000 to 2,000 IU daily. The upper level for safe vitamin D intake has not been well defined but is probably as high as 250 μg (10,000 IU) daily but in clinical practice, supplementation with this dose of vitamin D is rarely required.

Physicians who encourage their patients to take vitamin supplements should also educate their patients regarding healthy lifestyle and about healthy nutritious diet. Foods contain many additional important components, such as fiber and essential fatty acids and vitamin pills cannot be a substitute. Vitamin pills do not compensate for the massive risks associated with smoking, obesity, or inactivity, say the authors of the NEJM.

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Genetically Engineered Frankenfish is Considered Safe

A fish jumping out of the water. (Hemera/Thinkstock)
A fish jumping out of the water. (Hemera/Thinkstock)

Have you heard of “frankenfish”? It is a Frankenstein fish. Yuck, right? Well, have no fears. A media report including one in the Washington Post (December 21/2012) says, “Federal health regulators say a genetically modified salmon that grows twice as fast as normal is unlikely to harm the environment, clearing the way for the first approval of a scientifically engineered animal for human consumption.”

The Canadian Press reported on January 4, 2013, “Canadian ‘frankenfish’ moves closer to FDA approval for human consumption.”

In the U.S., the Food and Drug Administration (FDA) said the fish is unlikely to harm populations of natural salmon, a key concern for environmental activists. The AquaAdvantage salmon has been called by the critics as frankenfish. They see the development of frankenfish unethical and worry it could cause human allergies and eventually destroy the natural salmon population if it escapes and breeds in the wild.

FDA has said in the past that animals that are cloned are safe to eat. But frankenfish is not a clone. The DNA has been changed to produce a desirable effect. There is added growth hormone from the Pacific Chinook salmon that allows the fish to produce growth hormone all year long. Typical Atlantic salmon produce the growth hormone for only part of the year. The company says frankenfish will have the same flavour, texture, colour and odour as the conventional fish.

This is only one example of genetically altered food. There are many other foods which have been genetically changed. The Health Canada website (http://www.hc-sc.gc.ca/) says, “Health Canada conducts a thorough safety assessment of all biotechnology-derived foods to demonstrate that a novel food is as safe and nutritious as foods already on the Canadian marketplace.” Internationally, more than 10 species specific consensus documents have been developed, including for corn, soybean, wheat, rice, canola and sugar beet to ensure safety of these foods for human consumption.

As of 2012, Health Canada has approved over 81 genetically modified foods for sale in Canada. No applications have been turned down as long as they meet Health Canada’s strict guidelines. According to Wikipedia, commercial sale of genetically modified foods began in 1994, when Calgene Inc. first marketed its Flavr Savr delayed ripening tomato. Since then the technology has been used in different areas. There are organisms which have been genetically engineered and there are crops which have undergone genetic changes.

Some fruits and vegetables have been genetically changed to prevent disease in the crops. For example, Papaya has been genetically modified to resist the ringspot virus. Today, 80 per cent of Hawaiian papaya is genetically engineered. As of 2005, about 13 per cent of the zucchini grown in the US was genetically modified to resist some viruses. Most vegetable oil used in the US is produced from genetically modified crops. We can go on. There are many such examples. No reports of ill effects have been documented in the human population from genetically modified food.

Looks like genetically modified food is here to stay. And we are eating it every day.

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A sign of peace on earth?

Sunburst on Christmas Day (Dr. Noorali Bharwani)
Sunburst on Christmas Day (Dr. Noorali Bharwani)

Sunburst on Christmas Day (Dr. Noorali Bharwani)

Here I am, sitting in my sunroom, having breakfast on Christmas Day and suddenly I see a sunburst through the trees in the backyard. I said to myself, “Does this have some meaning? Does this say there is hope for peace on earth and happiness for all mankind?” May be. Who knows. We can always hope for something like that.

Cheers. Enjoy the holidays and have a Happy New Year!

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Use of Melatonin in Prevention and Treatment of Jet Lag and Chronic Insomnia

A businessman trapped in his seat by a sleeping passenger. (Digital Vision)
A businessman trapped in his seat by a sleeping passenger. (Digital Vision)

I have discussed the use of melatonin In my previous articles on jet lag and sleep disturbance. Since I am interested in this subject, my attention was drawn to an article in November 20 edition of the Canadian Medical Association Journal (CMAJ) titled, “Five things you should know about melatonin” by Carter and Juurlink from the University of Toronto.

The small pineal gland in our brain secretes a hormone called melatonin. Its main functions are to regulate the circadian rhythm and initiate and maintain sleep. Circadian rhythms are physical, mental and behavioural changes in our body that follow a roughly 24-hour cycle. It responds to light and darkness in our environment. Exposure to light also regulates the levels of melatonin which peaks at two in the morning.

Studies have shown that melatonin is effective against jet lag. The benefit was greater when flying eastward and when crossing more time zones. The critical question is the dose and when to take it. Some studies suggest the timing of administration of melatonin needs to be precise and individualized.

One study has shown that melatonin was effective in helping people fall asleep at doses of 0.3 milligrams (mg). To treat the jet lag, the recommended dose of melatonin is 0.3-0.5 mg, to be taken the first day of travelling. If you take too much of it then it can cause sleepiness, lethargy, confusion, and decreased mental sharpness. People with epilepsy, and patients taking warfarin should avoid melatonin due some reports about possible interaction.

A 2002 Cochrane Database System Review titled “Melatonin for the prevention and treatment of jet lag” by Herxheimer and Petrie says, “Nine of the ten trials found that melatonin, taken close to the target bedtime at the destination (10pm to midnight), decreased jet-lag from flights crossing five or more time zones. Daily doses of melatonin between 0.5 and 5mg are similarly effective, except that people fall asleep faster and sleep better after 5mg than 0.5mg. Doses above 5mg appear to be no more effective.”

Can melatonin be used for chronic insomnia? Studies have shown melatonin increased total sleep time by 12.8 minutes, increased sleep efficiency by 2.2 per cent and decreased sleep latency by 4.0 minutes. It does not sound very impressive. There is no clinical consensus on the use of melatonin in cases of insomnia.

Melatonin is sold over the counter and it is synthetic. It is the only human hormone available in Canada without a prescription. Melatonin should be used with caution.

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