Most dietary supplements are designed to provide our daily requirements of vitamins and minerals, expressed on packaging as a percentage of the Reference Nutrient Intake (RNI). This is the amount that is thought to be enough for virtually everyone, including those with particularly high requirements.Other measurements used are Estimated Average Requirement (EAR), set for average needs but recognizing that some people need more (see RNI), and that others need less, which is expressed as Lower Reference Nutrient Intake (LRNI), the amount needed by Supplements are usually those with low needs. However if you habituall eat (or take) less than LRNI you are likely to find that you are deficient.When taking food supplements it is important to follow the doses stated on the package in order to prevent any dangers of overdose and to avoid imbalances. All nutrients work in conjunction with others, and with substances in the body, so taking too much of one vitamin, mineral, or other food supplement could upset the balance of delicate mechanisms within the body such as enzyme production. Minerals that could be harmful, however, are rarely sold except on prescription.As a general rule, vitamins and minerals work "synergistically." That means they both need each other to work properly and that neither works as effectively on its own. A classic example is the combined effect of vitamin C and the mineral zinc, which is used in the treatment of the common cold and influenza.In most cases food supplements should be taken with or just after meals (exceptions are amino acids, which are most effective taken on an empty stomach).You should avoid taking iron pills with certain antibiotics. Check with your supplier about the suitability of taking supplements with medication you are taking.Based on the findings, published in today's issue of the Journal of the American Medical Association (JAMA), the researchers warned that consumers should be cautious about taking supplements containing the nutrients. At least 150 million Americans regularly take dietary supplements that often include antioxidants.Hot Coffee, Tea and SpicesHabitual drinking of liquids that are too hot, or consuming an excess of irritants such as coffee, tea or pickles and spices can cause inflammation of the digestive linings, resulting in a drop of secretion of digestive fluids and poorer extraction of vitamins and minerals from food. hose Over 50 Years of AgeThose over 50 should take multivitamin supplements without iron, Pleuss says. These are often marketed as "senior supplements."To strengthen their bones and prevent osteoporosis, Pleuss recommends this group add two vitamins, B12 and D, as well as the mineral calcium. According to the National Institute on Aging, more than 10 million Americans have osteoporosis, and another 18 million more have lost enough bone to make them more likely to develop it. Although most of these 28 million are women, 5 million men are at risk, too, and they suffer one-third of all hip fractures, as well as spine and wrist fractures.