Minerals

Did you know?

Iron from chicken and meat is easier for our bodies to use than iron from vegetables.

Quick facts

• Minerals can affect the absorption of each other – this means you must be careful when taking multiple supplements.
• Minerals are less likely than vitamins to be lost through cooking.
• Many Kiwis are not getting enough iodine in their diets.
• Fortification of stock food in New Zealand and eating imported foods, like Aussie wheat and Brazil nuts, help maintain healthy selenium levels.
• Coffee, tea and bran all decrease iron absorption – so have them between meals. 
• For healthy bones, eat calcium rich foods, cut salt and alcohol intake, remain smoke free and exercise regularly.
• Many Kiwis eat more than the recommended daily upper limit of sodium (salt), which comes from salt included in many processed foods and some drinks. Read food labels, choose low sodium products, reduce salt in cooking and avoid snacking on salty foods. Try not to add salt at the table.
  

What are minerals?

Minerals are inorganic compounds essential to all living things. They are found in the soil and hence end up in our food supply. If a country’s soil is poor in a certain mineral, there may be the need to fortify (add specific nutrients or minerals) animal feed or certain foods.

Bone minerals

Calcium and phosphate, both are needed in relatively large amounts. Calcium is also needed in large amounts for muscular activity. Fluoride, although not essential, helps prevent tooth decay by forming a compound which stabilizes the mineral matrix in teeth.

Electrolytes

Sodium, chloride, potassium and magnesium, all highly soluble and needed for such things as controlling water balance, muscle contraction and conducting nerve impulses.

Trace elements

Iron, iodine, selenium, chromium, manganese, molybdenum and copper, are essential and needed in very small amounts. Except for chromium, each of these is incorporated into enzymes or hormones required in metabolism. Trace mineral deficiencies are uncommon in developed countries, with the exception of deficiencies of iron and zinc. However, in New Zealand selenium and iodine soil levels are low, so precautions need to be taken. All trace minerals are toxic at high levels, and some (arsenic, nickel, and chromium) may cause cancer.

Minerals of dietary importance to New Zealanders

B12

• Vitamin B12 (also called cobalamin) belongs to the B vitamin group. It is important for normal blood and nerve function. 
• Vitamin B12 plays a part in making folate (vitamin B9).
• Both vitamin B12 and folate are essential in the manufacture of DNA (our genetic material).

Calcium

• Calcium is vital for strong bones and is deposited in our bones until our mid-20s.
• Our bones serve as a ‘bank’ and later in life we draw calcium out to meet our needs.
• It's important to get enough calcium, otherwise we can be left with brittle bones which easily break (osteoporosis).

Vitamin D

• Vitamin D is important for strong bones, muscles and overall health.
• Vitamin D is sometimes called the sunshine vitamin because our bodies produce it in response to sunlight.
• It can also be found in some foods like fish, eggs and fortified dairy products.
  

Folic acid

• Folate/folic acid is a B vitamin important for cell growth and reproduction. It is found naturally in leafy vegetables, citrus fruits, wholemeal bread, yeast, liver and legumes (peas, beans, lentils, chickpeas etc.)
• Folic acid is the man made (synthetic) form of folate used in supplements and fortified foods and drinks. It is easier for the body to absorb and use folic acid than naturally occurring food folate.
• Folic acid can help to ensure healthy development of babies in early pregnancy.

Iron

• Your body needs iron for your red blood cells to carry oxygen around your body and for proteins in your muscles. 
• Iron helps your immune system to fight infections, and is important for growth and brain development in children and for healthy brain function in adults.

Salt (sodium) & Iodine

• Most New Zealanders eat about 10 times more salt (sodium) than they need.
• While most of us should use less salt, ie, less sodium, in our diets, we also need more iodine.
• Nutritionists say first focus on lowering your sodium intake, then take a look at ensuring you are getting enough iodine. 
• Table salt in New Zealand is iodised to ensure we avoid the damaging effects of iodine deficiency, which was common here before the 1950s.

Selenium

• Selenium is a trace element important for the control of thyroid hormone metabolism, reproduction and immunity. 
• Selenium works with vitamin A as an antioxidant helping to prevent our body from damage.  

Zinc

• Zinc is important for our immune system.
• Zinc helps our bodies make proteins and DNA (the genetic material in all cells).
• Zinc helps with wound healing, senses of taste and smell, and for growth and development during pregnancy, as a baby and as a child.

Learn more

Eat Food. Not too much. Mostly plants. NZ Herald, 2008 
Minerals NZ Nutrition Foundation

References

Cochrane Review – low sodium good for those with problems, but not sure about effect on healthy people The Cochrane Collaboration, 2011
Nutrition facts NZ Nutrition Foundation