These are the ones most people probably need to be concerned about if their diet isn’t as good as it could be.
Calcium supports the structure of bones and teeth and helps to regulate blood pressure, as well as being needed by muscles, blood vessels and hormones and for sending messages throughout the nervous system. Inadequate levels of calcium, as well as vitamin D, contribute to the development of osteoporosis and fractures, so it’s a particularly important mineral for seniors, especially women.
However, you won’t find calcium at a 100% RDI dose in a multivitamin — it’s so bulky the pill would be too big to swallow. So if you want to increase your calcium intake, you’re better off doing it in your diet or looking for a specific supplement.
Main food sources: Dairy products, fish with bones (especially salmon and sardines), nuts, legumes (beans, including baked beans, lentils), tofu (if it’s made with calcium sulphate). It’s also found in smaller amounts in broccoli and leafy greens.
Iron is essential for oxygen transportation in the body and a deficiency can result in fatigue, poor work performance and decreased immunity. Prior to menopause it’s an important mineral for women to keep an eye on, and vegetarians and endurance athletes might benefit from a supplement. But most other adults get plenty of iron from their diet and don’t need supplements — in fact too much iron can cause or mask other health problems.
Ferrous iron salts (ferrous fumarate, ferrous sulphate and ferrous gluconate) are the forms of iron supplements that the body can absorb best. Absorbing iron from non-meat sources like supplements is boosted by vitamin C, so take them with a glass of orange juice.
Main food sources: Iron comes in two forms — haem iron and non-haem iron. The haem form is absorbed more readily by the body: sources include liver, red meat and chicken, and fish to a lesser extent. Good sources for non-haem iron are nuts, legumes, apricots and whole grains.
Zinc helps protect the body’s immune system and is important, particularly for men, for the reproductive system. It’s also thought useful for promoting wound healing.
Main food sources: Oysters and other seafood, meat, liver and eggs are the best sources. It’s also found in nuts, legumes and whole grains.
An important antioxidant, vitamin A comes in two main ways: either as ready-to-go preformed vitamin A (such as retinol) found only in animal foods; or pro-vitamin A, which is turned into vitamin A in the body and is mainly found in plant foods (for example, beta carotene, which is most common). Pregnant women shouldn’t take it in the retinol form, as this is linked to a risk of birth defects. Excessive retinol (over 1500 µg/day) has also been implicated in reduced bone density or increased hip fracture risk. Two studies have suggested that men who are smokers and take high-dose beta carotene supplements have an increased risk of lung cancer.
Main food sources: It’s chiefly found in liver and cod liver oil; some is also in oily fish, eggs, milk, butter and cream. The body can also easily convert it from the beta carotene in dark green vegetables and orange and red fruits and vegetables. It’s usually added to margarines.
Vitamins B6, B12
Vitamin B6 is needed to make haemoglobin to carry oxygen and also help to maintain normal blood sugar and serotonin levels. Vitamin B12 is needed to make DNA. Along with folate, low levels of vitamins B6 and B12 are risk factors for cardiovascular heart disease, and can result in anaemia and neurological disturbances. Taking a supplement of B6 may also reduce the severity of PMT and morning sickness.
Main food sources: For B6, wheatgerm, fish, bananas, meat, legumes and nuts. And per milligram, Vegemite is one of the richest sources of B6. For B12, liver, kidney sardines, oysters, egg yolk, fish, meat, cheese and milk.
Folate (Folic Acid)
One of the B vitamins, folate (or its synthetic form, folic acid) is especially important for pregnant women (in fact for all women who might get pregnant) as it’s been proven to help reduce the level of neural tube defects (like spina bifida) in the developing foetus. Low levels may also be a risk factor for cardiovascular heart disease and colon and breast cancer. Clinical trials are currently under way to determine whether folate supplementation can lower the risk of coronary heart disease.
Main food sources: Fresh green leafy vegetables, asparagus, organ meats, legumes, oranges, nuts and folate-fortified cereals.
More on folate ...
We need to eat vitamin C on a regular basis, as humans are one of the few species of animal that can’t make it. It’s also one of the most important antioxidant substances in the body, maintains the body’s connective tissue, and is essential for the formation of collagen, the major element of blood vessels, skin, tendons, cartilage and teeth.
Some studies suggest that taking vitamin C supplements long-term may help prevent heart disease. It may also play a role in cancer prevention. Any role vitamin C might have in the prevention and treatment of the common cold remains hotly debated, but a recent Cochrane Review analysis of 29 vitamin C studies concluded that it doesn’t appear to prevent colds, but may have a modest role in reducing their duration and severity.
Main food sources: It’s in many fruits and vegetables, the most concentrated sources being blackcurrants, red capsicum, guava, pawpaw, oranges and strawberries.
Vitamin D is made in the body by exposure to sunlight. Along with calcium, low levels of vitamin D contribute to the development of osteoporosis and fractures, so this is important for seniors, particularly women. There’s no Australian RDI for vitamin D (because there’s thought to be little danger of anyone not getting enough exposure to the sun). However, anyone who’s housebound or not exposed to direct sunlight for at least one to two hours a week is recommended to take a supplement of 10 µg/day. Elderly people in particular should make sure their diet contains enough. Pregnant women shouldn’t take large doses.
Main sources: Apart from exposure to sunlight, small amounts are also found in oily fish like herring, salmon, tuna and sardines, beef liver, fortified margarine, eggs and cod liver oil.
This is considered to be the most important and potent fat-soluble antioxidant. It’s best known for its effects on the cardiovascular system and may have a role to play in preventing cardiovascular disease, though recent research suggests having enough in your diet is better than supplements. High-dose vitamin E supplements have also been tested in clinical trials for pain relief of rheumatoid arthritis and osteoarthritis, with varying results.
Main food sources: Vegetable oils, particularly wheatgerm oil, nuts and seeds. It’s also found in eggs, soya beans, and fruit and vegetables to a lesser extent.