When it comes to nutritional benefits, vitamins have long stood front and centre. But what about those equally important essential mineral workhorses that labour under cover with no recognition?
We’re talking about trace minerals, compounds needed – albeit in microscopic quantities – to keep your body running as nature intended. And, tragically, living in the shadow of the cocksure, attention-seeking vitamin big boys, such as A, C and D.
‘Vitamins and minerals are both categorised as micronutrients, but there are some
clear distinctions between the two,’ says nutritionist Tom Irving.
‘Vitamins are organic compounds that contain carbon and are derived from plants or animals. We have to consume them because our bodies can’t naturally make enough of them or, in the case of E and D, can’t make them at all.'
'Minerals, on the other hand, are inorganic substances that have never been living and which can’t be destroyed by heat and/or cooking. Macro-minerals are needed in larger quantities – typically in excess of 100mg per day – whereas trace minerals are needed in very small amounts, often below even 1mg per day.’
Unlike vitamins, there are no non-essential minerals, meaning you have to get them all via your diet. But while you’ll probably be au fait with where to find your vitamin C hit – hint, it involves your five a day – when it comes to minerals, things get a bit murkier.
‘For minerals, fruits and vegetables aren’t always the best sources,’ explains Professor Margaret Rayman, professor of nutritional medicine at the University of Surrey.
And, although trace minerals are, typically, harder to be lacking in, certain current food trends – swerving dairy, for example – could put you at risk of deficiency, symptoms of which include chronic fatigue, cognitive decline and depression.
Time to acquaint yourself with some of the key essential minerals.
1/ Iodine: The thyroid manager
Nutritional gains?
Think of this as your almighty mineral. Not only is it crucial for neurological development from day dot, it also plays a major role in healthy thyroid function.
Without it, your active thyroid hormone, triiodothyronine (which is quite the multitasker, involved in metabolic rate, heart and digestive functions, muscle control, bone maintenance and brain development), wouldn’t exist.
Yet, according to the latest National Diet and Nutrition Survey (NDNS), 15% of women have iodine intakes below the lower reference nutrient intake level (LRNI to its friends) – thanks, in part, to the rise of alt milks, which typically have just 2% of the iodine concentration of cow’s milk.
Which foods is it in?
White fish and dairy products. Vegan? While the main sources of iodine do come from seafood, you don’t necessarily need to supp up.
‘Sprinkling iodised salt on meals is an effective method of meeting your body’s requirements should you be concerned about deficiency,’ says Irving. ‘Couple this with the consumption of fortified foods, such as bread, and supplements are often not needed.’
How much should I eat?
Aim for 0.14mg per day. Not too much because high doses can cause thyroid problems over the long term. A 200ml serving of milk provides 0.05-0.1mg and 100g cod has 0.19mg. If you do want to take a supplement, Irving suggests a quality multivitamin containing potassium iodide or sodium iodide.
2/ Copper: The fat burner
Nutritional gains?
According to research published in Nature Chemical Biology, copper is essential for metabolising fat.
In the 2016 study, researchers found that the more copper participants had in their bodies, the more fat was broken down – although, as yet, exactly what biochemical mechanisms are at play is unclear. It’s also proven as a brain booster; deficiency has been linked to Alzheimer’s.
Which foods is it in?
Sunflower seeds, cashew nuts, green olives and shellfish.
How much should I eat?
Aim for 1.2mg per day – you can meet this requirement with two 30g handfuls of cashew nuts. Careful you don’t exceed it, though.
Too much copper can cause stomach pain, sickness and diarrhoea, and if levels remain high over an extended period of time, it can damage your liver and kidneys.
3/ Selenium: the immune system helper
Nutritional gains?
If your nose is perma-snotty or you’re trying to conceive, pay attention. Selenium boosts immune system function and is a key player in egg formation and fertilisation. But 47% of women have intakes below the LRNI, according to the NDNS 2018. Poor show.
Which foods is it in?
Brazil nuts and eggs.
How much should I eat?
Women should aim for 0.06mg a day (0.075mg if you’re breastfeeding), which you’ll get by eating three Brazil nuts a week (not per day, as many think), or in a daily multimineral.
But beware: too much can lead to selenium poisoning, symptoms of which include hair loss and skin and nail discolouration. No thanks.
4/ Molybdenum: The liver lover
(repeat after us: Mol-ib-den-um)
Nutritional gains?
Have a tendency to go hard instead of going home when the mood takes you? Listen up.
‘Alcohol often contains sulphites, which can damage the body,’ says Duane Mellor, senior lecturer in human nutrition at Coventry University and spokesperson for the BDA.
‘Molybdenum supports an enzyme called sulphite oxidase, which is integral to the conversion of toxic sulphites into more inert sulphates, which the body can then excrete in the urine.’
Which foods is it in?
‘Foods that grow above ground are higher in molybdenum than those that grow below,’ says Irving. Think cauliflower, beans, potatoes and oats.
How much should I eat?
0.065mg, which you’ll easily meet with 100g of potatoes.
5/ Manganese: The bone booster
Nutritional gains?
This one is essential for bone health and, as shown in a study by the University of California, can help to reverse bone mineral density loss (which kicks in from your thirties, you’ll be thrilled to learn) when taken as part of a calcium, copper and zinc supplement.
The reason? ‘Manganese activates glycosyl transferases, an enzyme needed for the formation of proteoglycan molecules, present in cartilage,’ explains Professor Rayman.
Which foods is it in?
‘Tea is probably the simplest source for many people,’ says Professor Rayman. Not really a tea person? Try porridge with cinnamon or cloves instead.
How much should I eat?
Aim for 3mg per day. ‘One or two mugs of tea would be plenty,’ adds Professor Rayman.
Correction: an earlier version of this article stated that Tom Irving is a dietitian. This was incorrect – he is a nutritionist.
