WE know that sugar-filled juices and canned drinks such as cola and lemonade can cause tooth decay - yet few of us would think fizzy vitamin preparations can have similar effects. However, a study at the University of Helsinki on eight types of effervescent vitamins found they could all have corrosive effects on teeth. Leaching out the minerals contained in teeth, they left them weaker, more porous and prone to decay. In the research, teeth were soaked in the vitamin drinks for 100 hours. All of them - including those drinks that contained calcium - caused demineralisation. The effects were worst in the Vitamin C products, where teeth were corroded so severely that dentine, the sensitive layer beneath the enamel was exposed. 'When you drink fizzy vitamins, you wouldnt expose your teeth for anything near this length of time, says Dr Mervyn Druian, spokesperson for the British Dental Association. 'However, if you drink one of these dissolved tablets each day, it is likely that they would weaken your teeth. Citric acid, the primary ingredient of many fizzy vitamin drinks, has been found by researchers at the University of Baltimore Dental School to cause dental erosion. While this erosion is less than in drinks that also contain sugar, it is still significant. 'Dental erosion is caused by acidic solutions which come into contact with the teeth, says Dr Adam Thorne, dental surgeon at the Harley Street Dental Studio. 'Because the critical pH of dental enamel is 5.5, any solution with a lower pH value may cause erosion, particularly over a long period or if it is taken regularly. 'The danger of these soluble vitamins is that they are marketed for daily use and consumers tend to take them with breakfast and brush their teeth shortly after. 'For an hour after you have an acidic drink such as a fizzy vitamin, cola or apple juice, your tooth enamel will remain softened, says Dr Thorne. 'During this period, teeth become more vulnerable to corrosion, sensitivity and decay. Vitally, if you brush your teeth during this time, you are likely to brush away a layer of tooth enamel. So how can you protect your teeth from the effect of fizzy vitamins? The strength of teeth changes continually over the course of a day, with minerals being leached out and replaced according to the foods you eat and drink. 'Whenever we have an acidic drink, minerals are leached out of the teeth to help neutralise the acid. Saliva is slightly alkaline, so it also has a neutralising effect, says Dr Druian. Daily Mail 'After a few hours, the neutralising action of saliva takes over, and calcium and other minerals are gradually put back in the teeth. Dairy products such as cheese and milk have an alkaline pH that help neutralise acids. They also contain minerals. Eating these after an acid drink will help reduce acid levels and remineralise teeth at a faster rate. Black tea has a neutral pH. Drunk with milk, it can serve as a good tooth protector, washing away acids from your mouth. But if you feel soluble vitamins are helping your health, there is no need to give them up, unless your teeth are already showing signs of erosion, says Dr Druian. 'You can minimise your risk of acid erosion by eating cheese or yogurt or having a cup of tea after a fizzy vitamin drink, he says. 'Give your teeth time to rebuild their mineral content. 'Dont brush your teeth for at least an hour and dont swish the fizzy vitamin drink around your mouth. You can also chew some sugar-free gum to increase the flow of saliva. 'Ultimately, if you are worried about the effects of these vitamins on your mouth, drink them through a straw or switch to a vitamin pill. DM