Do you know your minerals?

Updated: Aug 30, 2021


Part 2 (read part 1 here)

Calcium

Iron

Zinc

Iodine

Selenium



fruits and minerals


“Vitamins and minerals” tend to go hand in hand when we think of healthy diet promotion and supplementation. However, vitamins and minerals are not the same. Vitamins are organic nutrients, and minerals are inorganic nutrients. The presence or absence of carbon is what differentiates organic from inorganic nutrients.


Some minerals are necessary for the diet, others, not so much, thus the potential for a deficiency depends on the mineral itself. We all have different requirements, according to our age, sex, and physiological state (e.g., pregnancy/illness/stress). Examples of minerals include calcium, copper, fluoride, iodine, iron, magnesium manganese, phosphorous, potassium, selenium, sodium, and zinc. Six of the main minerals are discussed in further detail below:


Calcium


1) Calcium: the most abundant mineral in the body. Did you know, the skeleton contains about 99% of the body’s calcium![1] The body needs adequate dietary calcium to develop and maintain healthy bones and teeth throughout life. It is also essential for several vital bodily functions such as blood clotting, regulating heartbeat and nerve transmission. To protect against deficiency, you also need adequate amounts of vitamin D, the nutrient that allows you to absorb calcium (alongside several other nutrients such as vitamin K).



calcium rich milk


Food sources: bread is an important source in the UK because most bread flour (not wholemeal), is fortified with calcium by law. Other sources include green leafy vegetables such as broccoli and cabbage (but not spinach), dairy products such as milk, cheese and yoghurt, fortified soya products and fish eaten with the bones such as sardines, tinned salmon, and whitebait.

Daily reference value (DRV): adults aged 19 to 64 need 700mg a day.


Iron


2) Iron: iron is essential for your body to make haemoglobin in red blood cells, which carry energy-sustaining oxygen to every tissue. A lack of dietary iron can eventually lead to iron deficiency anaemia, the most common nutritional deficiency condition in the world.[2]Mild iron deficiency leaves you feeling tired and weak and may also inhibit intellectual performance.


Food sources: dietary iron is found as either haem iron (from animal sources), or non-haem iron (from plant sources). Haem iron is the more bioavailable form, as absorption of non-haem iron is negatively affected by various factors in food such as phytate, fibre, tannins, and calcium. Vitamin C, present in fruit and vegetables, aids the absorption of non-haem iron when eaten at the same time, as does meat. Liver, red meat, pulses, nuts, eggs, dried fruits, poultry, fish, whole grains, and dark green leafy vegetables are all sources of iron.



iron rich dinner


DRV: 8.7mg a day for men over 18, 14.8mg a day for women aged 19-50, and 8.7mg a day for women over 50.


Zinc


3) Zinc: an adequate supply of zinc is vital as it is involved in the major metabolic pathways concerned with protein, lipid, carbohydrate, and energy metabolism and is also essential for growth and tissue repair and for normal reproductive development. In addition, zinc is required for the structure and function of the skin, and hence plays a vital role in wound healing, which heal more slowly when you don’t get enough zinc. This includes the tissue damage caused by working out! A lack of zinc may also weaken your immune system, increasing your risk of infections.

Food sources: zinc is most readily absorbed from meat, which provides about a third of zinc in the UK diet. It is also present in milk, cheese, eggs, shellfish, wholegrain cereals, nuts, and pulses. For cereals and pulses, zinc’s availability is limited by phytates.[3]

DRV: 9.5mg a day for men over 18 and 7mg a day for women.


Iodine


4) Iodine: essential for keeping our thyroid healthy, which impacts many processes in the body including our metabolism. Your thyroid absorbs and uses iodine to make thyroid hormone. It also plays a vital role in the healthy brain development of a foetus and baby, so iodine requirements increase for pregnant & breastfeeding women. A moderate iodine deficiency leads to goitre (a swollen thyroid gland) and reduced production of thyroid hormones.



Food sources: seaweed, sea-fish such as haddock, cod, tuna and prawns, shellfish, iodised salt, yoghurt, milk, and eggs. Iodine can also be found in plant foods such as cereals and grains but check the label as levels vary depending on the amount of iodine in the soil where the plants were grown. Some plant-based milk are also fortified with iodine, but if you are following a strict vegan diet and do not eat any fish, eggs or dairy then you may want to consider taking an iodine supplement.

DRV: adults need 140ug of iodine a day.







Selenium


5) Selenium: The main function of selenium is to protect the body against oxidative damage. It is also necessary for the use of iodine in thyroid hormone production, for immune system function and for reproductive function. In the UK, intakes are low in most age groups for both men and women with 25–76% falling below the recommended amounts.

Food sources: look to include bread, fish, meat, eggs, grains, seeds, and nuts. Just two brazil nuts a day will provide you with your complete daily requirement of selenium. DRV: adults need 55ug of selenium a day.


Most people should be able to get all the nutrients they need by having a varied and balanced diet, although some people may need to take extra supplements.



Abigail is our associate nutritionist who aims to address myths around nutrition and empower her clients to make more informed nutritional choices, and educate her clients and help them regain control so they are able to make better decisions about their health and well-being.


“The truth is we ALL need guidance and support to change our lives and realise our goals.”


Abigail’s particular interests are in gut health, and she works on both weight management, diabetes and heart health. As well as supporting athletes and active individuals to meet their nutritional requirements Book online Abigail's expertise.


[1] Kovacs, C.S., 2001. Calcium and bone metabolism in pregnancy and lactation. The Journal of Clinical Endocrinology & Metabolism, 86(6), pp.2344-2348. [2] Camaschella, C., 2015. Iron-deficiency anaemia. New England journal of medicine, 372(19), pp.1832-1843 [3] Lestienne, I., Besançon, P., Caporiccio, B., Lullien-Péllerin, V. and Tréche, S., 2005. Iron and zinc in vitro availability in pearl millet flours (Pennisetum glaucum) with varying phytate, tannin, and fiber contents. Journal of Agricultural and Food Chemistry, 53(8), pp.3240-3247.