Currently, every Australian is missing one or more key micronutrients at the expense of their health; read on to see how nutrient deficiencies can affect our body’s physiology.
Many Australians follow a healthy lifestyle, which includes regular exercise and healthy eating. Many of these health-conscious Australians also regularly consume multivitamin supplements. But, for many of these healthy Australians, micronutrient deficiencies are lurking in their bodies. For example, about 23% of all Australians have Vitamin D deficiencies, and one in every five (18.3%) women of childbearing age have an iodine deficiency. And this is just the tip of the iceberg.
Part of the problem comes from deep down into our history. Western Australian soils are naturally infertile and low in nutrients, which requires farmers to follow a carefully managed fertilising approach. Likewise, Australia-wide, about 70% of our soils are classified as arid or semi-arid, meaning there is not much productive soil available for agriculture and farming. Also, as described in this article, our soils are very old. They have gone through slow but constant weathering and erosion, which has dissolved and washed away large quantities of nutrients such as phosphorous, calcium and potassium.
Another big part of the problem is that most Australians follow a poor diet. Australians of all ages generally do not eat enough of the five food groups recommended by the Health department. We also eat too many discretionary foods, which are morsels high in salt, fat and sugar. This poor diet, particularly the inadequate intake of fruit and vegetables, is an important risk factor for conditions like cardiovascular disease (CVD), type 2 diabetes, chronic kidney disease (CKD) and unhealthy weight (overweight and obesity).
We need to change our eating habits and taste preferences, move away from salty and sweet foods, and focus more on “rainbow food”. An easy way to find healthy fruits and vegetables is to follow their colour. Red capsicum, apples, tomatoes, green leafy vegetables, purple blueberries, and other produce contain phytonutrients, compounds that give plants their colours and unique taste. Eating more of these colourful fruits and vegetables will bring more key nutrients into our bodies, improving our health.
Nutrient deficiencies in Australia
The food we eat has a major influence on our health. Optimal nutrition leads to healthy body weight, protects against infection, and reduces the risk of chronic conditions and premature death. Australia has great national dietary guidelines promoting optimal nutrition and health outcomes. However, Australian statistics on nutrition are worrisome and suggest that most of us are not following these guidelines. According to the Australian Institute of Health and Welfare, some key facts about Australians and nutrition include:
- About 99% of Australians aged 2–18 and 9 in 10 adults aged 19 and over do not eat the recommended daily serves of vegetables.
- About 77% of Australians aged 19–50 do not eat the recommended daily serving of fruit.
- About 33% of Australians’ energy intake comes from discretionary foods, which are high in energy but low in nutrients.
- About 81% of males aged 51–70 are overweight or obese – in most cases due to diet.
- Most girls and women in Australia have a deficiency in iron and calcium intake.
- Overall, children of all ages eat too many unhealthy, discretionary goods, consume excessive sodium and do not eat enough vegetables.
- Adults aged 19-30 do not eat the recommended daily serves of all five food groups (veggies, fruits, grains, meats and milk products); they eat too many discretionary foods and too much sodium. Also,
- More than 44% of men and 71% of women don’t consume enough calcium.
- About 38% of women consume inadequate amounts of iron, and about 11% and 12% have insufficient intakes of dietary folate and iodine, respectively.
- Older adults follow a similar pattern: low intake of all five food groups, too many discretionary foods and sodium, and low calcium intake.
Micronutrient deficiencies and supplements
Australians are one of the world’s largest consumers of dietary supplements, including multivitamins, single vitamins, single minerals, herbal supplements, and oil supplements.
A 2017 study found that, among Australians, 47% of women and 34% of men reported using dietary supplements2. Furthermore, the study found that supplement use was higher among females, older adults, those with higher education levels and adults from areas of relatively high socioeconomic status.
However, even if you eat a well-balanced diet and take nutritional supplements, you could still miss out on some key micronutrients. In our modern world, it is easy to end up eating processed foods that look healthy but are low in basic micronutrients and high in sugars and fats.
Assessing our food intake and looking out for signs of nutritional deficiencies is an important first step to optimise our health and prevent short- or long-term health problems.
Symptoms of Nutrient Deficiency
Micronutrients are vitamins and minerals needed by the body in very small amounts. Yet, their effect on our body’s physiology can be huge. For example, micronutrients are essential components of enzymes and hormones, which are needed for the normal growth and development of the body. People affected by nutrient deficiencies can exhibit a wide range of symptoms, depending on the specific micronutrient(s) missing. Some typical symptoms associated with micronutrient deficiencies include:
- Anxiety and Restlessness
- Fatigue and tiredness
- Aches and pains
- Brittle hair and nails
- Irritability
- Depression
- Brain fog
- Acne
- Hair loss
- Slow wound healing
- Bone pain
- Irregular heartbeats
- Poor night vision
Some examples of symptoms and conditions linked to specific micronutrients include:
- Severe iodine deficiency can lead to brain damage and can cause stillbirth, spontaneous abortion and congenital anomalies during pregnancy.
- Moderate iodine deficiency – can cause mental impairment.
- Vitamin A deficiency – this is a leading cause of preventable blindness in children.
- Iron deficiency – can cause tiredness, weakness, a weakened immune system, and impaired brain function.
- Vitamin D deficiency – can lead to muscle weakness, bone loss, and an increased risk of fractures.
- Vitamin B12 deficiency – can cause megaloblastic anemia, a type of blood disorder that enlarges red blood cells. It can also cause impaired brain function and elevated homocysteine levels, which is a risk factor for several diseases, like osteoporosis, atherosclerosis, heart disease, and more.
- Calcium deficiency – common symptoms include soft bones (rickets) in children and osteoporosis in older adults.
What are the most common nutrient deficiencies?
Below we outline key information about seven of the most common micronutrient deficiencies3.
Vitamin D
This fat-soluble vitamin helps the body absorb and retain calcium and phosphorus, two key components needed for bone growth. Vitamin D has also been shown to reduce cancer cell growth, help control infections and reduce inflammation.
Vitamin D deficiency is the most common micronutrient deficiency affecting Australians and the most common problem we treat at AUSCFM. Globally, vitamin D deficiency is a common problem, with one recent study estimating that about 72% of the general population in Abu Dhabi were deficient in this vitamin4. Another international study reported that severe vitamin D deficiency in the USA, Canada and Europe reached nearly 6%, 7.4%, and 13%, respectively5. According to this study, moderate deficiency levels of this vitamin were 24% for the USA, 37% for Canada and 40% for Europe.
In Australia, a 2012 study reported that about 31% of adults have inadequate vitamin D status. The study reported that this figure could rise to more than 50% during winter and spring.
The two main factors causing vitamin D deficiency are:
- Lack of sufficient exposure to the sun and, to a lesser degree,
- following a nutrient-poor diet.
Other factors potentially leading to vitamin D deficiency include6:
- Skin complexity – people with naturally dark skin have a higher risk of developing vitamin D deficiency.
- Certain medical conditions that interfere with vitamin D absorption.
- Certain medications that affect our body’s capacity to break down vitamin D
- Certain genetic predispositions.
Low levels of vitamin D have been linked to multiple conditions, including:
- cardiovascular disease
- cognitive impairment in older adults,
- severe asthma in children
- certain cancers
- type1 and type 2 diabetes
- hypertension
- glucose intolerance and
- multiple sclerosis.
- 5 micrograms (200 IU) for children, adolescents and adults aged 19–50 years
- 10 micrograms (400 IU) for adults aged 51–70 years, and
- 15 micrograms (600 IU) for adults over 70 years of age
- mild = 30 to 49 nmol/L
- moderate = 12.5 to 29 nmol/L
- severe = lower than 12.5 nmol/L.
Magnesium
Magnesium is used in over 300 biochemical reactions in the body. It helps to:
- maintain normal nerve and muscle function
- maintain a healthy immune system,
- keep a healthy heart
- strengthen bones
- adjust blood glucose levels
- produce proteins and energy
- support optimal sleep, digestion, and mental health
Globally, it is estimated that around 10% – 30% of the population have some degree of magnesium deficiency. In Australia, data from the ABS estimated that in 2011-12, one in three people aged two years and over (37% of males and 34% of females) did not meet their requirements for magnesium.
Below, we highlight the Australian guidelines for optimal, suboptimal and excessive magnesium levels in the body, along with associated conditions.
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Generally, the causes behind magnesium deficiencies are grouped as extra-renal or renal.
- Extra-renal causes – These include conditions that cause decreased gastrointestinal absorption of magnesium, such as inflammatory bowel disease, chronic pancreatitis and alcoholism.
- Renal causes – these generally involve genetic conditions, such as Bartter’s syndrome and Gitelman’s syndrome. Certain drugs can also cause renal wasting of magnesium.
In Australia, the NPS recommends total magnesium concentration levels (mmol/L) of 0.7-1.0. According to these guidelines, levels of up to 2.1 do not lead to adverse conditions or symptoms.
Magnesium is the second most frequent deficiency treated at AUSCFM.
Iodine
Iodine is required for the production of thyroid hormones. Hence, it is important for normal growth and development, particularly for the brain.
Globally, it is estimated that more than 1.9 billion individuals have inadequate iodine nutrition (defined as urinary iodine excretion <100 (μg/L). In Australia, 2% of males and 8% of females aged two years and over had inadequate intakes of iodine, according to the ABS. In adults aged 19 years and over (2% of males and 10% of females), iodine deficiency is higher than amongst children aged 2-18 years (0.4% of males and 2% of females).
Typically, deficiency of iodine causes swelling of the thyroid glands in the neck. Also, this deficiency can lead to suboptimal production of thyroid hormones, which can cause:
- fatigue
- increased sensitivity to cold
- constipation
- dry skin
- weight gain
- puffy face
- muscle weakness
- elevated blood cholesterol levels
- pain or stiffness in the muscles and joints
- slowed heart rate
- thinning hair
- depression
- poor memory
- altered menstruation in women
The human body does not synthesise iodine, so diet is the primary source of this micronutrient. The best dietary sources of iodine include:
- fish
- eggs
- nuts
- meats
- bread
- dairy products
- seaweed
- iodised table salt
- beans
- legumes
- green vegetables
- shellfish
The World Health Organization (WHO) considers a population iodine deficient if the median urinary iodine concentration (UIC) is less than 100 μg/L. Adults typically require 150 micrograms (mcg) per day. Pregnant and breastfeeding women need 200 mcg per day. In Australia, data from the ABS shows that Australian adults had a population median of 124.0 μg/L of iodine, with men having a higher median UIC than women (131.0 μg/L compared with 118.0 μg/L).
Vitamin B12
Vitamin B12 plays a role in everything from making DNA to regulating brain function. Vitamin B12 is required:
- For the development, myelination, and optimal function of the central nervous system
- For healthy red blood cell formation
- For DNA synthesis [1,4,5].
- As a cofactor for two enzymes, methionine synthase and L-methylmalonyl-CoA mutase
Despite its importance, our body does not synthesise vitamin b12. Instead, we need to acquire it through our diet.
Worldwide, it is estimated that about 6% of adults under 60 years of age have some degree of vitamin b12 deficiency. In contrast, among adults over 60 years, prevalence is estimated at around 20%. However, there is a lot of variation in prevalence due to socioeconomic factors. For example, in Kenyan school children, the prevalence is 70%, and in East Indian preschool-aged children, vitamin b12 deficiency reaches 80%.
In Australia, one study found that adults in residential aged care facilities had a prevalence of about 14%9. In the general Australian population, a 2014 study found a prevalence of 26% 10.
Deficiency of this vitamin affects multiple systems and can result in anything from mild fatigue to severe neurological problems. Some reported clinical symptoms associated with vitamin b12 deficiency include:
- Cutaneous – such as hyperpigmentation, jaundice or vitiligo
- Gastrointestinal – such as glossitis
- Hematologic – such as anemia (macrocytic, megaloblastic), leukopenia, pancytopenia, thrombocytopenia, and thrombocytosis.
- Neuropsychiatric – such as areflexia, cognitive impairment (including dementia-like symptoms and acute psychosis), gait abnormalities, irritability, loss of proprioception and vibratory sense, olfactory impairment and peripheral neuropathy.
A poor diet is a major factor driving this deficiency. Foods like meat, eggs and milk are rich in this vitamin. Other important factors behind vitamin b12 deficiency include:
- Low stomach acidity
- SIBO (Small Intestinal Bacterial overgrowth)
- Pernicious Anemia – this is a type of autoimmune disease.
- Certain genetic mutations, such as the MTHFR mutations.
- Deficient levels of ‘intrinsic factor’, a protein secreted by the stomach. This protein is responsible for transferring vitamin b12 into the bloodstream. Without this protein, vitamin b12 cannot be absorbed, and it is disposed of as waste.
- Endocrine-related autoimmune disorders, such as diabetes or thyroid disease, may increase the risk of developing pernicious anemia.
- Crohn’s disease or celiac disease may interfere with the absorption of this vitamin.
- Certain parasites, such as tapeworms, can be behind vitamin b12 deficiency.
Internationally, recommended levels of vitamin b12 range from 0.4 mcg for infants up to six months of age to 2.4 mcg for adults over 19 years of age. Below is a table for recommended levels across all ages in the USA:
Recommended Dietary Allowances (RDAs) for Vitamin B12 [1]
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In Australia, vitamin b12 levels of 200-900 pg/mL (130-850 pmol/L) are considered in the normal range, according to the department of health.
Iron
Iron is a component in a wide variety of metabolic processes, such as oxygen transport, deoxyribonucleic acid (DNA) synthesis, and electron transport. Iron is commonly found in the body bound to proteins, such as hemoglobin, myoglobin, flavin-iron enzymes, transferring, and ferritin (Abbaspour et al., 2014). Our body uses iron for:
- synthesis of the oxygen transport proteins, hemoglobin and myoglobin
- Formation of heme enzymes
- Synthesis of iron-containing enzymes involved in electron transfer and oxidation-reductions
Iron deficiency is considered the most common nutritional deficiency in children, affecting more than 30% in resource-limited nations of Asia and Africa. In Australia, a 2008 study reported an iron deficiency prevalence of 10.6% among females under 50, 2.8% for females over 50, and no significant iron deficiency among males (Ahmed et al., 2008). More recently, a 2020 report showed that about 34% of Australian women, who are of childbearing age, and 5% of healthy males are iron deficient.
About 25% of people worldwide have anemia, and iron deficiency is the most common underlying factor among them. People with this condition cannot synthesise optimal levels of hemoglobin, which is the body’s key oxygen-carrying protein. Typical symptoms include general weakness and tiredness.
The main consequence of iron deficiency is a suboptimal capacity to transfer oxygen to every part of the body where it is needed. Some typical symptoms include:
- Tiredness
- Paleness
- Shortness of breath
- Headaches and dizziness
- Heart palpitations
- Dry hair and skin
- Restless legs
- Brittle fingernails
Some of the most common causes of iron deficiency include:
- Poor diet – this could involve a diet lacking foods rich in dietary iron, called “haem iron”, found in animal tissue, such as meat, poultry or fish. Plant-based food contains a different type of iron, called non-haem iron, which is not easily absorbed by the body. Some good sources of iron include:
- Meats, like beef, pork, poultry and fish
- Liver and kidney are rich in iron
- dark green leafy vegetables such as broccoli
- raisins
- nuts
- dried beans
- Vitamin C, which increases iron absorption
- Blood loss – if you have a heavy period or have donated blood, you can lose a significant amount of iron.
- Pregnant – If pregnant or breastfeeding, you will need to increase your haem iron intake.
- Exercise – regular exercise increases the body’s need for iron, as more red blood cells are produced, and iron is lost through sweating.
- Genetics – some people might have some genetic or physiological predisposition to absorb iron poorly, leading to a need to increase the intake of iron-rich foods.
The recommended daily dietary intake of iron, according to Australian guidelines, include:
- Babies 0 – 6 months – 0.2 mg/day
- Infants 7-12 months – 11 mg/day
- Children 1-3 years – 9 mg/day
- Children 4-8 years – 10 mg/day
- Children 9-13 years – 11 mg/day
- Boys 14-18 years – 11 mg/day
- Girls 14 – 18 years – 15 mg/day
- Women 19-50 years – 18 mg/day
- Pregnant women – 27 mg/day
- Breastfeeding women aged over 18 years – 9 mg/day
- Breastfeeding women aged 14–18 years – 10 mg/day
- Women aged 51 years and over – 8 mg/day
- Men aged 19 years and over – 8 mg/day
To measure your levels of iron, a ferritin test can be performed. Ferritin is a blood protein that contains iron, and the ferritin test allows your doctor to measure how much iron your body is storing. The normal range for blood ferritin is:
- For men, 24 to 336 micrograms per litre
- For women, 11 to 307 micrograms per litre
Zinc
Zinc is an essential mineral that is naturally present in some foods; it is involved in many different aspects of cellular metabolism, including:
- For the catalytic activity of approximately 100 enzymes
- a role in immune function
- helps with protein synthesis
- involved in wound healing
- required for DNA synthesis and cell division
- support for normal growth and development during pregnancy, childhood, and adolescence and
- it is required for a proper sense of taste and smell
Zinc deficiency is characterised by:
- growth retardation
- loss of appetite
- impaired immune function.
In severe cases, zinc deficiency causes:
- hair loss
- diarrhea
- delayed sexual maturation
- impotence
- hypogonadism in males
- eye and skin lesions
In some cases, zinc deficiency can cause:
- Weight loss
- delayed healing of wounds
- taste abnormalities, and
- mental lethargy
Diet is the primary zinc source and the leading cause of deficiencies. Other factors involved include:
- genetic predispositions – these can lead to poor absorption of dietary zinc
- Age – older people may not absorb nutrients like zinc well. Newborns might also need support if they are premature or sick.
According to the nutrient reference values for Australia and New Zealand, the recommended levels of dietary intake for iron are:
- Babies 0 – 6 months – 0.2 mg/day
- Infants 7-12 months – 3 mg/day
- Children 1-3 years – 3 mg/day
- Children 4-8 years – 4 mg/day
- Children 9-13 years – 6 mg/day
- Boys 14-18 years – 13 mg/day
- Girls 14 – 18 years – 7 mg/day
- Men all 19+ – 14 mg/day
- Women 19+ – 8 mg/day
Oysters contain more zinc than any other food. Other good sources of iron include red meat and poultry, beans, nuts, certain types of seafood (such as crab and lobster), whole grains, fortified breakfast cereals, and dairy products.
Recently, with the COVID-19 pandemic, it has been shown that people with low levels of zinc tend to have worse health outcomes if infected with the COVID-19 virus. One study found that Zinc deficient patients developed more complications (70.4% vs 30.0%, p = 0.009) (Jothimani et al., 2020). For a good general review on Zinc and human health, see Roohani et al. (2013).
Calcium
Calcium is the most abundant mineral in the body. It is the basic component of bones and teeth and allows normal bodily movement by keeping tissues rigid, strong, and flexible. Calcium is also involved with blood vessel contraction and dilation, muscle function, blood clotting, nerve transmission, and optimal hormonal secretion.
Calcium deficiency can lead to reduced bone strength and osteoporosis. Other symptoms include:
- Rickets in children
- Other bone disorders in adults
- osteomalacia, defective bone mineralisation and bone softening
Calcium deficiency can occur due to:
- vitamin D or magnesium deficiency, as low levels of these micronutrients, results in impaired calcium absorption.
- impaired parathyroid hormone (PTH) production leading to hypoparathyroidism
- impaired bone resorption of calcium
- critical illness, or
- certain medications, like bisphosphonates, cisplatin, or proton pump inhibitors
According to Australian recommendations, the optimal level of dietary calcium intake is, in mg/day:
- Babies 0–6 months – breastfed – 210 mg
- Babies 0–6 months – formula fed – 350 mg
- Babies 7–12 months – 270 mg
- Children 1–3 years – 500 mg
- Children 4–8 years – 700 mg
- Children 9–11 years – 1,000 mg
- Adolescents 12–18 years (including pregnant and breastfeeding young women) – 1,300 mg
- Women 19–50 (including pregnant and breastfeeding women) – 1,000 mg
- Women 51–70 – 1,300 mg
- Men 19–70 – 1,000 mg
- Adults over 70 – 1,300 mg
At AUSCFM, we consider that the best approach to avoiding calcium deficiency is through a diet rich in calcium. Organic dairy products are recommended, if well tolerated, as well as salmon, sardines, beans, lentils, broccoli, sesame seeds, Chinese cabbage (bok choi) and kale.
Do you have a nutrient deficiency?
Micronutrient deficiencies can be inconspicuous and go unnoticed until a more significant problem develops. To be on the safe side, the best approach is to consult with your doctor or health practitioner and get tested.
At AUSCFM, we perform comprehensive testing, the most advanced testing protocols available in Australia. Our goal is to identify which nutrients are under or overrepresented and design a personalised nutritional plan to address any issues. In addition, we perform DNA-based tests to identify genetic mutations that can potentially lead to poor nutrient regulation.
Nutrient Deficiencies at AUSCFM
At AUSCFM, we follow a modern and evidence-based approach to diagnosing and treating pathologies associated with micronutrient deficiencies. We are on top of current research on micronutrients’ role in human health. We employ leading diagnostic testing technologies to identify nutritional deficiencies, as well as other markers of health. Our patients have routine blood testing yearly to track micronutrient levels. Regular blood work allows your doctor and health care practitioner to stay on top of any deficiencies you may develop.
In addition to testing for micronutrient deficiencies, we employ advanced testing that targets six additional gut pathologies. Taken together, the results of these seven tests will give us a comprehensive view of the factors influencing a patient’s health and will help us design personalised treatment strategies.
In parallel, getting an in-depth understanding of your current health and lifestyle, including the diet you follow, can help clinicians identify the root of your problems. Working closely with your practitioner and health coach, you can resolve the underlying cause of hormone imbalance with a personalised plan, including changes to your nutrition, lifestyle, and stress management practices.
If you are experiencing health problems that could be explained by hormonal imbalances, start by registering to
References
- Australian Institute of Health and Welfare. (2018). Nutrition across the life stages. Canberra: AIHW. Read it!
- Burnett, A. J., Livingstone, K. M., Woods, J. L., & McNaughton, S. A. (2017). Dietary Supplement Use among Australian Adults: Findings from the 2011-2012 National Nutrition and Physical Activity Survey. Nutrients, 9(11), 1248. https://doi.org/10.3390/nu9111248 Read it!
- Australian Institute of Health and Welfare. (2019). Poor diet. Retrieved from https://www.aihw.gov.au/reports/food-nutrition/poor-diet. Read it!
- Al Zarooni, A.A.R., Al Marzouqi, F.I., Al Darmaki, S.H. et al. Prevalence of vitamin D deficiency and associated comorbidities among Abu Dhabi Emirates population. BMC Res Notes 12, 503 (2019). Read it!
- Amrein, K., Scherkl, M., Hoffmann, M. et al. Vitamin D deficiency 2.0: an update on the current status worldwide. Eur J Clin Nutr 74, 1498–1513 (2020). Read it!
- Nowson, C. A., McGrath, J. J., Ebeling, P. R., Haikerwal, A., Daly, R. M., Sanders, K. M., … & Mason, R. S. (2012). Vitamin D and health in adults in Australia and New Zealand: a position statement. Medical journal of Australia, 196(11), 686-687. Read it!
- Marcinowska-Suchowierska, E., Kupisz-Urbańska, M., Łukaszkiewicz, J., Płudowski, P., & Jones, G. (2018). Vitamin D Toxicity-A Clinical Perspective. Frontiers in endocrinology, 9, 550. https://doi.org/10.3389/fendo.2018.00550. Read it!
- DiNicolantonio, J. J., O’Keefe, J. H., & Wilson, W. (2018). Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis. Open heart, 5(1), e000668. https://doi.org/10.1136/openhrt-2017-000668 Read it!
- Mirkazemi C, Peterson GM, Tenni PC, Jackson SL. Vitamin B12 deficiency in Australian residential aged care facilities. J Nutr Health Aging. 2012 Mar;16(3):277-80. Read it!
- Moore,E, Pasco,J, Mander,A, Sanders,K, Carne,R, Jenkins,N, Black,M, Schneider,H, Ames,D and Watters,D 2014, The prevalence of vitamin B12 deficiency in a random sample from the Australian population, Journal of investigational biochemistry, vol. 3, no. 3, pp. 95-100. Read it!
- Abbaspour, N., Hurrell, R., & Kelishadi, R. (2014). Review on iron and its importance for human health. Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences, 19(2), 164–174. Read it!
- Ahmed, F., Coyne, T., Dobson, A., & McClintock, C. (2008). Iron status among Australian adults: findings of a population based study in Queensland, Australia. Asia Pacific journal of clinical nutrition, 17(1). Read it!
- Jothimani D, Kailasam E, Danielraj S, Nallathambi B, Ramachandran H, Sekar P, Manoharan S, Ramani V, Narasimhan G, Kaliamoorthy I, Rela M. COVID-19: Poor outcomes in patients with zinc deficiency. International Journal of Infectious Diseases. 2020 Nov 1;100:343-9. Read it!
- Roohani N, Hurrell R, Kelishadi R, Schulin R. Zinc and its importance for human health: An integrative review. Journal of research in medical sciences: the official journal of Isfahan University of Medical Sciences. 2013 Feb;18(2):144. Read it!