Good reliable sources of information on vitamin supplements are hard to find as so many studies on the subject are found to be less than independent, often due to sponsorship by interested parties. One doctor related how he had received the results of one study, which claimed the common cold was not affected by doses of vitamin C. This was an interesting conclusion until the doctor realized the study had been financed by a producer of cold remedies.
Often it is said that supplements are unnecessary as all the nutrition required can be found in a healthy diet. Of course this is quite correct but how many people can be said to eat a healthy, balanced diet? Opinions even vary as to what is a healthy diet. Recent advice has centred on five portions of fruit and vegetables a day but it has now been suggested that eight portions might be a better figure.
Supermarkets provide the fresh produce consumed by many people but doubts have been expressed about the nutrition in mass produced fruit and vegetables. In a previous role, I worked for such a supermarket chain and found anecdotal evidence that pointed to growing methods restricting the benefits of produce. Many varieties of fruit and vegetables are grown in conditions where the growing days are shortened by artificial means in order to accelerate production. This results in the expected vitamins and minerals not having time to accumulate.
The nutritional needs people have vary according to environmental conditions. Lifestyle factors including stress, smoking, and heavy pollution change the demand for different nutrients, as do medical conditions.
Recently there has been concern over possible vitamin overdoses or poisoning (hypervitaminosis). The culprit often seems to be vitamin A often found in the liver of animals. The livers of polar bears, seals, walruses and huskies are particularly rich in vitamin A and therefore too dangerous for human consumption, which the Inuit have a particular problem with of course! Vitamin C should not be taken in extremes as it can have a laxative effect and some strains of vitamin B should be used in moderation. The problem is not a widespread one though with more deaths from swallowing laundry products in the USA than from hypovitaminosis. In most years there are no deaths from vitamin overdose at all. However it is better to be sensible over their consumption.
The brands of supplements available can vary enormously. One feature to look out for is the coating of the tablet. Some cheap products have a sugar coating, which causes the tablet to pass through the body without dissolving. I understand complete vitamin pills are often found in lavatories. One way to find out if the tablets you use will break down in the gut is to immerse one in a glass of water. It should dissolve within an hour.
On the whole you get what you pay for so often the more expensive natural dietary supplements are the more effective choice. Some come in powder form thus ensuring they are absorbed into the body faster and more completely.
Natural dietary supplements can be a useful way to increase health but it is always worth doing a little research and investigating the RDA (Recommended Daily Allowance) for each vitamin or even consulting a healthcare professional before choosing.