Repsol YPF

In general, modern diets usually show some gaps when it comes to minerals and vitamins essential for the well functioning of our organism. Daily consumed foods contain different quantities of carbon hydrates, proteins, fats, vitamins and minerals, but no single food can supply all the necessary nutrients. Therefore, a balanced diet should include a wide variety of foods from each group in the food pyramid.       However, around 10 % of the Spanish population prefers to frequently consume vitamin supplements as a way to fight stress, physical and mental exhaustion, or an inadequately balanced diet. This is still a very low percentage if compared to the United Kingdom (39%) or Germany (43%). Experts say that vitamin consumption is increasing, especially in the spring and fall, and it is usually self-medicated while ignoring a proper diet. It should also be considered that not all vitamin supplements are natural, as they are produced in laboratories and chemically synthesized due to the combination of diverse chemical products.       Vitamins are regulating elements in our body and are very important in biological processes, but do not provide calories. The organic system does not produce them in itself but they are vital and so must be obtained through certain foods because the human body cannot synthesize them. As an exception we find vitamin D, formed in our skin when exposed to sun light, and also vitamins K, B1, B12, and folic acid, which is formed in the intestinal flora in small quantities. There are two kinds of vitamins: fat-soluble (A, D, E, and K), soluble in fat and oils, and water-soluble (C and B complex).       In special cases it is necessary to take vitamin supplements, such as in vegetarian diets, or in persons with some kind of food allergies who need long term supplements of B12. During pregnancy, the need for vitamins B1, B2, B6 and folic acid increases. Once the baby is born and during lactation the levels of vitamin A, B6, D, C and folic acid should be controlled so that they are sufficient. As children get older they should always take enough vitamin A, C, D, B1, B2 and folic acid. It is also advisable to take vitamin D if they do not go out and do not receive direct sun light. Suffering illnesses affecting the digestive system, surgery on the stomach or kidney failure are good reasons to take supplements. Side effects
 Taking vitamins supplements should be controlled because, although it is not common, there could be side effects: Excessive consumption of vitamin A could produce liver diseases and in pregnancy it could pose a hazard for the foetus and miscarriage. In children, the toxicity of this vitamin could cause headaches, nausea, vomiting, dizziness, double sighting and brain oedema. High doses of vitamin B6 (pyridoxine) could cause severe damage of nerve sensibility, especially in women taking a high dosage of this vitamin to ease premenstrual syndrome symptoms. As for vitamin C, high doses could cause kidney stones or anaemia. Toxicity levels of vitamin D could cause high levels of calcium in the blood, constipation, kidney problems, nausea, weakness and kidney stones. High levels of vitamin E could potentiate the anticoagulant action of coumarin, increasing the risk of haemorrhages. Also a high dose of iron provokes nausea and diarrhoea, and pancreas, liver and heart problems.