Vitamin Supplements and Balance in Diet
Vitamin C supplement probably wouldn’t be a bad idea. And vitamins A and E. Why not a little selenium too? And a solid dose of zinc every day can’t do any harm, can it?
In many countres people buy vitamin supplements for high amounts every year although they have plenty of supply of ordinary food. Is that money really well invested? Let’s see what the research shows.
Large population studies have shown that people who eat a lot of vitamins and antioxidants also have fewer illnesses.1 It has therefore been assumed that extra vitamins and antioxidants have positive health effects.
Population studies can indicate associations – in this case between high vitamin intake and health. But to get concrete “evidence” on cause and effect, experiments are usually required. In 1994 such an experiment was conducted where a group of smokers received supplements of the antioxidant beta-carotene and was compared with a control group.2
The researchers were fairly certain that the beta-carotene would reduce the cases of lung cancer. To their surprise it turned out that the group that took beta-carotene had 18% higher risk of getting lung cancer – and 8% higher risk of dying prematurely compared with the control group.
It was assumed that chance played a trick on the researchers. For that reason the study was followed up with an even larger investigation. Now, to be on the safe side, vitamin A was also added to the beta-carotene.
When the first data were analyzed the researchers’ jaws almost dropped. The results were in fact even worse than in the first study. As much as 28% in the vitamin group got lung cancer and the risk of dying prematurely was 17% higher than in the control group. The researcher saw no other way than to stop the study.3
Overall, the large collection of studies available today do not provide any evidence that high doses of vitamins or antioxidants protect against cardiovascular disease and cancer. On the contrary, beta-carotene and vitamin E tend to increase disease risk.1
High vitamin intake is a marker of a healthy lifestyle
How then could we explain the well-known connection between high vitamin intake and good health in the population? Most likely it is because people who eat a lot of vitamins, e.g. in the form of fruit and vegetables, also have a healthy lifestyle in general.
There may also be other substances in fruit and vegetables, for example fiber, that have positive health effects. High vitamin intake thus seems to be a marker of a healthy lifestyle in general, not the cause of the good health.1
Balance to achieve health
The vitamin studies highlight the importance of balance for achieving health. Both too little and too much of a good thing can be a hindrance.
Too few vitamins can lead to deficiency diseases. Older individuals sometimes need extra supplements of calcium and vitamin D to prevent osteoporosis, and people with poor nutrition may of course need specific vitamin supplements.4
But for the majority of people today, a balanced diet is sufficient in order to get the vitamins and antioxidants we need. Extra amounts can, as research shows, even be damaging.
It is often maintained that vitamins are natural – and therefore ought to be healthy. But eating bottled vitamins is not natural. We cannot “compensate” for a giant portion of French fries with a multi-vitamin tablet.
The huge amounts of money that we annually spend on vitamin supplements could probably be used for something more meaningful.
How can you get better balance in your eating habits?
1. Måns Rosén. Sanningen om mat och hälsa: vad säger forskningen?
2. Smigel k. J Nat Cancer Inst 1996;88:145
3. Statens beredning för medicinsk utvärdering. Att förebygga sjukdom med antioxidanter.
4. Nordic nutrition recommendations