| Sports and health enthusiasts are constantly throwing | | | | Mega-doses of iron can be lethal, as iron levels are |
| vitamin and mineral supplements down their necks but | | | | only controlled by what you eat, absorbed and what |
| the issue of whether they are really required is a topic | | | | comes out when you bleed. Zinc in high amounts can |
| of considerable debate. | | | | cause nausea and vomiting. There are many cases of |
| Vitamins and minerals, or micronutrients, are essential | | | | excess iodine intake causing goitre (an enlarged thyroid |
| nutrients, as, broadly speaking, our bodies do not | | | | gland, making the neck swell up) and hyperthyroidism, |
| synthesise them, and so we have to obtain them from | | | | i.e. a racing metabolism. Too much fluoride can cause |
| our food. Micronutrients regulate metabolism and assist | | | | tooth and nail crumbling. These are just a few |
| in numerous physiological and biochemical functions. | | | | examples! |
| Insufficient intakes may lead to deficiency problems, | | | | Many vitamins and minerals are consumed in high |
| and in extreme cases, even death. | | | | doses for their antioxidant effects. Vitamins C and E, |
| If you are eating a healthy balanced and varied diet, | | | | beta-carotene and selenium are antioxidants, which |
| then evidence indicates, in most cases, you'll be okay | | | | have been shown to reduce incidence of heart |
| with no need for a supplement. Most alternative | | | | disease and some cancers. Antioxidants help stop the |
| nutritionists will claim that you do need supplements for | | | | oxidation process, which is part of the process of |
| 'optimum' health and to 'just to make sure you're | | | | certain diseases and ageing. People therefore believe |
| getting enough'. | | | | that consuming more of these antioxidants more |
| There has been loads of scientific research into the | | | | means reducing risk of disease further (and looking |
| debate to see if supplementation over and above | | | | younger!). But, studies have shown that there are |
| what you get from your normal diet is required in order | | | | optimal intake levels, and these levels are well below |
| to reduce risk of disease and/or maximise | | | | what many people supplement with. |
| performance. In a few cases the research is | | | | The American Food and Drug Administration (FDA) |
| conclusive and supplements are recommended, e.g. | | | | have concluded that the consumption of food in its |
| folic acid in pregnancy to reduce the risk of spina bifida | | | | natural form is ideal. In nature chemicals occur naturally |
| in the child. But it is only certain people that do have a | | | | in what is known as a 'biochemical redox system', |
| use for supplements; does this include all of us? | | | | which is where some food constituents act as |
| Sports enthusiasts are traditionalists for mega-dosing | | | | antioxidants and others act as pro-oxidants, so they |
| without any real reason for doing it. Beware that | | | | balance each other out. If there are too high levels of |
| certain vitamins can have harmful side effects if taken | | | | antioxidants in the blood, from consuming supplements, |
| in too large quantities. Vitamin C is frequently | | | | they can become pro-oxidant in certain circumstances, |
| mega-dosed on, but are you aware that too much for | | | | thereby increasing oxidation and risk of disease. |
| long a period can lead to kidney stones? As vitamin C | | | | Consuming too high intakes of antioxidant supplements |
| is water soluble, people have the misconception that | | | | may therefore have detrimental effects on health. |
| you cannot take too much - this is wrong! | | | | For these reasons for most people we recommend a |
| There are other examples: There have been cases of | | | | varied healthy balanced diet, with at least five servings |
| death from too much vitamin A; rare, but there are | | | | of fruit and vegetables daily. In certain circumstances, |
| many reports of hair loss, liver and bone damage. | | | | there may be a case for supplements, but in general a |
| Excess thiamine (vitamin B1) can cause headaches | | | | healthy diet should cover all. So before you order more |
| and irritability. Too much vitamin D can cause too high | | | | vitamin and mineral supplements, first check your diet |
| blood calcium levels, potentially causing muscle spasms. | | | | and eat more fruit and vegetables! |
| Consuming too much sodium raises blood pressure. | | | | |