The following groups of people may need to take vitamin supplements preferably multivitamins at the Australian RDI (recommended dietary intake) level, rather than as single nutrients.
- Vegans, because they eat no animal products, not even cheese or eggs, and may risk vitamin B12 deficiency.
- Women may need extra folate in the lead-up to conception and in the first trimester of pregnancy.
- Smokers, because their metabolism uses up to twice as much vitamin C as non-smokers.
- People on very low-fat diets risk deficiencies of the fat-soluble vitamins A, D, E and K.
- People on diets due to allergy or food intolerances.
- People recovering from major illness or surgery.
- People with diarrhoea, coeliac disease or pancreatitis.
- The elderly.
- Illegal drug users.
There are hundreds of ways to take supplements in liquid, tablet or capsule form, as fizzy drinks or in an oil base. You can even take some as additives in cereals, milk substitutes, juices, fruit drinks and snack foods. It’s generally accepted that B vitamins are assimilated better when taken as a complex. But don't self-diagnose talk to your GP.
Older people often need more of some nutrients because their bodies are not as efficient at absorbing or using nutrients from foods. Conversely, their energy needs are reduced because their body chemistry has slowed and they tend to be less active.
The elderly need a high-quality, nutrient-rich diet. The very old or those with certain medical conditions may need vitamin and mineral supplements for medical reasons. Veiled women and elderly people who have little exposure to sunlight may need vitamin D. Vitamin C can help keep tissue and bones healthy and ward off infection. Vitamin E and beta-carotene are recommended to prop up the immune system; calcium and iron for backache and tremors; C and A (retinol) for ageing skin. Zinc is often deficient in older people and may help heal wounds.
Pregnancy and breastfeeding
Pregnancy and breastfeeding increase a woman’s need for many but not all nutrients. Most experts agree that women should boost their vitamin intake before conception and during pregnancy. Multivitamins with iron and folic acid are good. Vitamin C helps with absorption of iron, so some recommend drinking orange juice with any iron supplement.
A new study has found that pregnant women who do not get enough vitamin E may give birth to children who are at higher risk of developing asthma. Children of women who had the highest intake of vitamin E in the trial were less likely to develop wheezing or asthma. Higher levels of zinc also seemed to help.
The most common deficiencies in pregnant women are calcium, folic acid (folate), iron and zinc. Dairy products are a rich source of calcium to protect bone mass and meet the baby’s needs as it grows. Folate is needed for the development of new cells and the recommended daily intake doubles during pregnancy. Folic acid taken before conception and for the first three months of pregnancy can help reduce the risk of neural-tube birth defects such as spina bifida. Iron deficiency increases the risk of having a premature or low-birthweight baby. Iron supplements are often prescribed in the third trimester. Zinc is needed to keep cells healthy. Women taking iron supplements may also need zinc because iron can interfere with absorption of zinc.
During breastfeeding, important nutrients are protein, calcium, vitamin C, folate, zinc, magnesium, vitamin B6 and fluids. Insufficient stores of iron during pregnancy may cause the breastfeeding mother to develop iron-deficiency anaemia.
Sportsmen and women
Increased physical activity allows for greater food intake, making it easier to attain required nutrients. Research has concluded that people who engage in strenuous exercise, such as marathon runners, may find that vitamin C prevents them from developing colds.
Without enough vitamin E, your muscles' cells begin to break down and some vitamins and minerals leach away, while excess calcium may be deposited in muscle tissue. Eat more oats, buckwheat, millet and/or linseed as porridge or in muesli. After exercise, try a high-carbohydrate diet of wholegrains, pasta and rice. These foods provide some of the thiamin needed to rid muscles of excess lactic acid.
Athletes and manual workers may need a supplement of potassium, which is lost in sweat. You can find it in celery, bananas, rockmelon and other fruit and vegetables.
Potassium deficiency can cause cramps, muscle injury and irregular heartbeat.
You also need sufficient iron from liver (first choice), oysters, lean meats, wholegrains, leafy green vegetables, beans, peas and dried fruit.
It's important for professional athletes and others who undertake regular strenuous exercise to have enough glutamine in their diets. Brewer's yeast is a rich source. Phosphorus deficiency is common, resulting in muscular weakness. The richest sources are cheese, nuts, meat, fish, eggs, legumes and milk. Magnesium aids coordination and speed of reaction.
Children and teens
Babies absorb calcium and zinc more readily from breastmilk than from formula. Adequate vitamin A helps ensure that bones achieve their correct length.
Children who live on junk food may be deficient in vitamins C, B1 and B6. Symptoms include dry skin, sleep disturbance, loss of appetite, learning difficulties and mood swings.
Children and teenagers need extra iron during growth spurts. Zinc, in combination with other nutrients, is needed for hormone production during puberty. Extra calcium is also required to cope with rapid growth. Additional nutrients should be available in a balanced diet.
Vegetarians and vegans
Vegetarians may be healthier than meat eaters, but this tends to be for lifestyle reasons rather than food intake. They may need to compensate for the restrictions they impose on their diet. When meat is eliminated from the diet, other high-protein foods such as pulses and beans are needed to replace it.
Fruit and vegetables provide a bonus in beta-carotene and vitamin C, but the phytate found in fibrous plants can make certain nutrients less available to them. Strict vegetarians should include in their diet foods rich in zinc, B12 and calcium.
It is impossible for vegans, who eat no foods of animal origin, to get vitamin B12. They may also need supplements of omega-3 fats. They may need to take supplements of protein and calcium because these are found only in meat and dairy products.
A British study found that vegetarian women need to make an effort to eat enough iron, B12 and vitamin D (the latter aids absorption of calcium). Iron and zinc tend to be unavailable from plant sources.
Smokers and heavy drinkers
Every cigarette smoked saps vitamin C. Acetaldehyde, a toxic substance found in tobacco smoke and produced by the body from alcohol, can destroy vitamins B6, Bl and C. Heavy smoking can immobilise vitamin Bl2.
The most common effect of alcohol abuse is vitamin B1 (thiamin) deficiency, which can eventually result in delirium tremens and brain damage. Alcohol abuse can also cause cirrhosis of the liver, which in turn causes excessive loss of the fat-soluble vitamins A, D, E and K as well as an increased need for B-complex vitamins.
Smokers and heavy drinkers often have low levels of beta-carotene. The mineral lithium produces an aversion to the taste of alcohol in most people. Brewer's yeast is a rich source of glutamine, which may curb cravings for alcohol. Glutathione, another amino acid, can protect the liver and lungs from the destructive effects of drinking and smoking.