With such emphasis placed on the pandemic, and on bacteria and viruses, it is easy to forget the more subtle triggers of illness. Among them, several pathologies result not from infection, but from imbalances in the essential trace elements the body needs to function. While they can be immediately less lethal, they are shockingly prevalent, impacting hundreds of millions of people around the world.

At the minute level, we are comprised of the same elements that constitute other lifeless substances, such as rocks, water, or natural gases. But as living entities, keeping the body healthy and in motion requires the regular addition of a great many components.

Setting aside metabolic basics like calories from food, to remain healthy people also need the right amounts of trace elements like iron, iodine, calcium — and by extension vitamin D from sunlight. There are even some non-essential elements, whose benefits for health must be weighed against their risks.

Notably, a number of diseases result from imbalances of these trace elements in the body. Many of the resulting conditions are challenging for health organisations to tackle, either due to the scale of the problem or the complexity of remediation.

Iron and Anaemia

Anaemia is a condition in which either the number of red blood cells in a person’s blood is reduced, or the oxygen-carrying haemoglobin inside these cells simply ceases to function correctly. Consequently, oxygen is not transported around the body at the levels needed. This can be experienced as fatigue, weakness, dizziness, or shortness of breath. And in children, anaemia is associated with cognitive impairment.

Among the most common causes of the condition is iron deficiency.

The World Health Organisation (WHO) estimates that the condition impacts 42% of the world’s children under 5 years of age; as well as 40% of pregnant women globally.

It is a massive problem, but there are a number of ongoing initiatives aimed at reducing its prevalence. One major strategy is nutrition awareness programs educating parents, and in particular mothers, about healthy eating. Another is through administering iron supplements.

In fact, iron supplements have been given to young children worldwide for decades. This was done in the belief that it had an entirely positive impact on their development, but this was without proper scientific evidence, according to Associate Professor Sant-Rayn Pasricha of WEHI.

The research institute has been collaborating with WHO in the fight against anaemia. A recent study has cast doubt over modern intervention practices.

“What we have demonstrated, is that while iron supplements improved anaemia in children, these interventions had no impact on growth, cognitive function, behaviour, or development,” explains Pasricha.

The WHO recommends iron supplements are given to all young children in low- and middle-income countries where anaemia is common. But Pasricha and other researchers believe that we need to carefully reconsider the indiscriminate use of these interventions based on new data.

Jena Hamadani from the International Centre for Diarrhoeal Diseases Research says that for some children, iron supplements may cause unanticipated negative outcomes.

“In children taking iron supplements who did not have anaemia, they may actually have had increased presentations to clinics due to episodes of diarrhoea, possibly indicating iron interventions were doing more harm than good,” Hamadani says.

This case demonstrates the considerable complexity and risk in balancing people’s consumption of essential elements.

Fluoride and Fluorosis

Fluorosis is a condition typically impacting dental health, mostly in children whose teeth are not yet fully developed. In very mild and mild forms, it is largely a cosmetic problem in which teeth spot or streak permanently with white marks.

In severe cases, dental fluorosis can completely discolour teeth and result in pits forming on their surface. In yet more acute circumstances, fluorosis can even present as a debilitating skeletal condition that weakens bones.

The dental form of this disease impacts hundreds of millions of people around the world. Skeletal fluorosis impacts fewer, but the number of cases continues to rest in the millions.

Fluorosis is most prevalent in several regions around the world, including South America, the west coast of the United States, North Africa, and Asia — particularly China and India. In many of these areas, fluorosis remains a concern due to limitations in local water treatment policies or facilities.

Fluorosis is caused by fluoride, a chemical ion of the element fluorine. Fluoride impacts the function of calcium, and by extension affects the enamel of teeth.  In India, for example — where some regions sit on a fluoride belt — approximately 25 million people are affected by fluorosis, and 66 million are at risk of developing the condition.

While the element is non-essential for humans, it has paradoxical impacts on dental health. Fluoride has a powerful protective effect on teeth when administered in small concentrations, guarding them against decay. For this reason, it has been used in dental products since this property was discovered. Fluoride is even added in low concentrations to drinking water in some countries, including the United States, the UK, Spain, and New Zealand. Remarkably, this health policy has been proven to protect populations from dental cavities.

There are many challenges in dealing with fluorosis. Chief among them is balancing the level of positive beneficial exposure, protecting dental health, with the negative consequences of fluorosis from too much exposure. This is complicated by the wide variations in localised fluoride levels in water and rock globally; and further, by the climate and dietary practices of different countries.

Hypothyroidism and Iodine

Iodine deficiency is another extremely common condition. Many people are low in iodine and do not know it, complicating diagnosis. Despite being another of the trace elements, iodine is extremely important to the proper functioning of the body.

Iodine is not found in many foods. Consequently, it is all too easy to eat a diet low in this trace element. This has a range of negative effects on health.

The body needs iodine to create thyroid hormone from the thyroid gland. Iodine deficiency inhibits this function, leading among other things to hypothyroidism. This condition causes a long list of symptoms including tiredness, weakness, difficulty learning and remembering, dry skin, and constipation. It can be treated with a synthetic form of thyroid hormone.

In women, iodine deficiency can also lead to serious fertility problems, even miscarriages and stillbirths, as well as putting a developing foetus at risk of nerve damage. Iodine deficiency is associated with brain damage to the foetus, intellectual disability, low IQ, and stunted growth.

The deficiency is generally easy to treat with iodine salts or iodine supplements. While treatment is simple, diagnosis is more challenging, as low iodine levels often go unrecognised. This makes iodine deficiency the number one preventable cause of mental retardation.

Given the severe and lasting consequences for babies, this is a troubling health issue. Especially in certain countries. Australia is known, for example, to have very low levels of iodine in local soils, leaving people at higher risk of iodine deficiency. Iodised salt is common in the country as an attempt to counter this, and since 2009 Australia began reinforcing all organics breads with iodine.

Women planning to be pregnant are encouraged to take supplements before doing so. And they are reminded not to take more than the recommended dosage, as this can once conversely impact the thyroid gland.


These are just a few of the more common conditions caused by imbalanced levels of trace elements in the body. It is important to note that while all 14 trace elements are known to be crucial for humans, many of their mechanisms of action in the body, and related pathologies, are not wholly understood. Research is ongoing in different areas, and it is highly likely that new causes and effects, and possible remedies — will be uncovered in the future.