Rosalee Brown
MANY PERSONS are unsure of the decision to make when it comes to taking dietary supplements. Supplements, as the word denotes, are to support, bolster or improve, and are not the 'be all or end all' of managing one's nutritional well-being.
Nutrients play an important role in nutritional well-being. Macro nutrients, such as proteins, carbohydrates and fats, and micro nutrients, which include vitamins and minerals, all have specific major roles, as well as complementary roles and are required in specific amounts, types and composition to carry out their functions.
It is important to note that taking too little of one nutrient can affect the major role of another, for example, insufficient intake of carbohydrates will cause proteins to be used for energy instead of its major role of building and repairing tissues. Too much of one nutrient can affect the balance of another. For example, high levels of zinc can impair the absorption of vitamin C.
Balance is very important, in that vitamin C enhances the absorption of non-heme (plant source) iron in the intestine, but excess iron in the presence of vitamin C can speed up the oxidative breakdown of vitamin C, rendering it incapable of enhancing iron absorption. This example does not only apply to vitamin C and is the same for many other nutrients. It is, therefore, reckless and dangerous to self-medicate with vitamins and minerals, because their major role is to enhance the skin, et cetera.
Vitamins and minerals are needed in very minute amounts, and for many, especially the water-soluble ones, absorption rate decreases with increased intake. Hormones, for example, tightly regulate the mineral, calcium and it also interacts with many other nutrients. For example, dietary proteins can both promote the loss and absorption of calcium, doubling protein intake can increase urinary calcium loss, and calcium supplementation can reduce non-heme iron absorption by up to 50 per cent.
These are some instances when supplementation may be required:
Menstruation - iron.
Pregnancy iron and folates.
Lactation increased
calories and some additional nutrients.
Chronic illness depend on illness and medication.
Smoking vitamin C.
Chronic dieters variety of nutrients depending on the restrictions.
Vegans B 12 and possibly iron (others based on individual's needs).
BEST PLACE TO GET NUTRIENTS
Food creates synergy and provides flavour and satiety.
TOXICITY
Fat-soluble vitamins are stored in the fat tissues and take a longer time to leave the system, so sustained high levels can lead to toxicity. Tolerable upper limits (UP) is the highest continuing intake of a nutrient that will likely pose no risk of adverse health effect for almost all individuals. As intake increases above UP, the risk of toxicity increases. Mega doses above UP are therefore unsafe.
HOW TO PRESERVE NUTRIENTS IN FOODS
Consume as unprocessed as possible (some processed foods are fortified).
Consume as close to harvesting as possible.
Preserve carefully so as not to destroy nutrients that are labile to heat, light, air or ageing, et cetera.
Buy properly preserved
vegetables.
Store properly for as short a time as possible.
Cook properly (do not overcook or undercook).
Combine well (for example, non-heme iron sources with vitamin C).
IS THERE A PLACE FOR SUPPLEMENTATION FOR HEALTHY PEOPLE?
Many may not consume an adequate diet daily, so a multivitamin can provide insurance in such cases. There is no need to spend a lot of money, as generic supplements are just as good. Read labels for additives, excess fillers and expiry dates. Be wary of unproven claims in supplements. Supplements and herbal concoctions do not come under the same strict regulations as pharmaceuticals.
Rosalee M. Brown is a registered dietitian/nutritionist who operates Integrated Nutrition and Health Services; email: yourhealth@gleanerjm.com.
