The old adage that good things come in small packages is certainly true for trace minerals. While some of these tiny nutritional powerhouses are poorly understood, others are known to be essential for everything from strong bones to a healthy heart.
What it is?
Trace minerals are those the body needs in only minuscule amounts. For example, though the average-sized person carries around approximately 1.5 kg of calcium, the trace mineral manganese, weighs in at only 0.18 g. Some trace minerals, such as copper, iron, magnesium, selenium and zinc, have been studied extensively and are included elsewhere in this book. Others, which are discussed here, include boron, fluoride, manganese, molybdenum, silicon and vanadium.
What it does?
The vast majority of trace minerals operate as coenzymes, which – in partnership with the proteins known as enzymes – facilitate chemical reactions throughout the body. They help to form bones and other tissues, contribute to growth and development, make up part of the genetic material DNA, and help the body to burn fats and carbohydrates.
Preliminary evidence suggests that some trace minerals are (like their big brother calcium) good for the bones and may help to prevent osteoporosis. With silicon, manganese helps to build strong bones and connective tissue, the durable substance that hold much of the body together. Boron may contribute to bone health by preventing calcium loss and activating the bone-maintaining hormone oestrogen, whereas vanadium seems to stimulate bone-building enzymes. Although fluoride is known mainly for its ability to prevent tooth decay, some studies suggest that it may also help to protect against bone fractures.
In addition to strengthening bones, manganese is part of enzyme superoxide dismutase – a potent antioxidant that plays a role in protecting cells throughout the body. furthermore, some evidence suggests that manganese may benefit people with epilepsy by reducing the likelihood of seizures. Researchers are investigating the possibility that silicon may help guard against heart disease. Blood vessel walls concentrate this mineral, and people who get more silicon in their diet may have a decreased risk of this disease. Because silicon also strengthens connective tissue, it's sometimes used to nourish hair, skin and nails. Molybdenum helps the body to use its stores of iron and assists in the burning of fat for energy. And vanadium may be beneficial for people with diabetes because of its ability to enhance or mimic the effects of the hormone insulin, which regulates blood sugar (glucose) levels.
Boron, silicon and fluoride :
- Treats heart arrhythmias, osteoporosis, epileptic seizures, sprains and back pain.
- May help people with diabetes.
- Helps the body to use iron.
Molybdenum may aggravate symptoms of gout.
Boron is available only on prescription in Australia and New Zealand. It can affect hormone levels and should be used with care by those at risk of cancer of the breast or prostate.
Manganese may be toxic for people with liver or gall-bladder disease.
Reminder: If you have a medical condition, talk to your doctor before taking supplements.
How much you need?
There's no RDI for many of the trace minerals, because scientific evidence is too scanty to provide a firm requirement. But for some of them, experts generally agree on an estimated safe and adequate daily dietary intake: for manganese, it's 2-5 mg; for fluoride, 3.1-3.8 mg; for silicon, 5-10 mg; for boron, about 1 mg; for molybdenum, 150-500 mcg; and for vanadium, 10 mcg.
If you get too little:
A fluoride deficiency makes people more prone to tooth decay, and a low boron intake may weaken bones. Deficiencies of manganese, vanadium and silicon (determined mostly from animal studies) can result in poor growth and development, imbalances in cholesterol levels and problems making insulin. Silicon holds water in tissues, so people with deficiencies often sweat more than normal.
If you get too much:
In most cases, there's no reason to take high doses of these trace minerals. However, the majority of them don't cause serious adverse reactions when ingested in large amounts. Manganese toxicity, which has been noted in people inhaling the metal in mines, can cause severe psychiatric disorders, violent rages, poor coordination and stiff muscles. High doses of boron (more than 500 mg a day) may result in diarrhoea, vomiting, nausea and fatigue. Too much vanadium (more than 10 mg daily) can cause cramping, diarrhoea and a green tongue.
How to take it?
Many bone-building formulas and multivitamin and mineral supplements contain varying doses of trace minerals. Most people don't need to take individual trace minerals, though single supplements such as manganese (up to 100 mg a day) are available.
Guidelines for use:
It's not clear whether certain factors affect absorption or whether one supplement form is preferable to another. Boron is probably best taken as part of a bone-building supplement that also contains calcium, manganese, magnesium and other minerals. Manganese absorption may be impaired by a high iron intake.
Manganese is present in whole grains, rice bran, sunflower seeds, nuts and leafy greens. Nuts and leafy greens also supply boron, as do broccoli, apples and raisins. Vanadium is found in buckwheat, shellfish, mushrooms, soya bean products and oats. Silicon is available in whole grains, turnips, beetroot, soya bean products and brans, including oat and rice bran.
- Some manufacturers claim that manganese gluconate is better absorbed than other forms of the mineral, but there's no real evidence to recommend one specific form over another.
- A substantial and safe natural source of silicon is vegetable silica, an extract of the herb horsetail.
- Trace minerals are often part of daily multivitamin and mineral supplements.
- A manganese-poor diet may increase the risk of heart disease, according to the preliminary results of a recent animal study from the University of Maine. Animals lacking this mineral produced less of a substance called glycosaminoglycan, an important component of the connective tissue found in arteries. The researchers hypothesise that this scenario makes LDL ('bad') cholesterol more likely to accumulate on artery walls.
Did you know?
Processed foods, such as white bread, contain less silicon than their wholegrain counterparts.