Vitamins and Minerals
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Vitamins and minerals are nutrients that humans use in very small quantities for metabolic processes. They are grouped together as micronutrients due to being needed in far smaller amounts than the macronutrients (proteins, carbohydrates and fats).1
Vitamins are organic compounds sourced from plants and animals. In contrast, minerals are inorganic and sourced from soil and water.1
In general, vitamins and minerals support the processes that allow for normal growth, development, metabolism and overall functioning of the human body.
Unlike macronutrients, vitamins do not provide energy. Instead, they have specific biochemical roles in metabolism. Importantly, the body is unable to synthesise vitamins in adequate amounts, and they must be consumed in adequate amounts through diet.
There are thirteen different vitamins:1
- Eight “B” group vitamins and vitamin C (water-soluble)
- Vitamins A, D, E and K (fat-soluble)
Table 1. An overview of water-soluble vitamins.1,2
|B1: Thiamine||Co-enzyme for dehydrogenase reactions in carbohydrate and amino acid metabolism||Wholegrain, cereals, pork and legumes||
|B2: Riboflavin||Co-enzyme in redox reactions (e.g. Krebs cycle)||Meat, fish, eggs, milk, green vegetables||
|B3: Niacin||Co-enzyme in redox reactions (e.g. Krebs cycle)||Meat, liver, cereals, seeds, legumes||
|B5: Pantothenic Acid||Co-enzyme A co-factor for acyl transfer reactions (e.g. fatty acid synthesis)||Organ meats, egg yolks, milk and broccoli||
|B6: Pyridoxine||Co-factor for decarboxylation reactions, glycogen phosphorylation and transamination||Meats, nuts, whole grains and vegetables||
|B7: Biotin||Co-factor for carboxylase reactions||Eggs, meat, fish, nuts and seeds||Rare
|B9: Folate||Co-enzyme for 1-carbon transfer methylation reactions
Nitrogen-base synthesis for RNA and DNA
|Green leafy vegetables, legumes||
|B12: Cobalamin||Co-factor for methylmalonyl-Co-A, methionine synthesis and DNA synthesis||Meat and dairy products||
|C: Ascorbic Acid||Hydrophilic antioxidant||Fruits and vegetables (uncooked)||Scurvy|
Table 2. An overview of fat-soluble vitamins.1,2
|A: Retinol||Vision, antioxidant, cell differentiation and specialisation||Organ meats, butter, egg yolks, green leafy vegetables||
|D: Calciferol||Calcium and phosphate homeostasis||Cholecalciferol: exposure to sunlight, fish, milk and plants
Ergocalciferol: plants, fungi, fortified foods
|E: Tocopherol||Antioxidant||Meat, eggs, oil, leafy vegetables||
|K: Phytomendione||Coagulation co-factor for clotting factor II, VII, IX and X, protein C and S||Green vegetables
Synthesis via intestinal flora
Vitamin D deficiency3
Vitamin D deficiency is one of the most common vitamin deficiencies. There are several causes, including lack of sunlight exposure, malnutrition (often from substance abuse), malabsorption disorders and chronic kidney disease.
Clinically, untreated vitamin D deficiency manifests as osteomalacia in adults and rickets in children. Other complications include hypocalcaemia and hypophosphataemia.
Supplementation of vitamin D is common, particularly in countries with low levels of sunlight, or where sun protection is important.
People most at risk of vitamin D deficiency are those living in residential/care homes or who are hospitalised, those with poor mobility, those with poor sun exposure and people with gastrointestinal diseases affecting absorption.
Like vitamins, minerals do not provide energy to the body. Minerals are unable to be synthesised and must be consumed.
Minerals are classed into two groups
- Major minerals: large amounts are needed
- Trace minerals: small amounts are needed
Mineral deficiencies range from being very common (e.g. iron deficiency) to very rare.
Table 3. An overview of the major minerals.4
|Calcium||Bone and teeth mineralisation, muscle contraction, blood clotting, blood pressure||Dairy products, canned fish with bones||Stunted growth, bone loss||Constipation, increased kidney stone risk|
|Potassium||Fluid and electrolyte balance, cellular integrity, muscle contraction and nerve impulses||All whole foods particularly bananas, avocado and tomato||Irregular heartbeat, muscular weakness, glucose intolerance||Muscle weakness, vomiting (hyperkalaemia)|
|Sodium||Fluid and electrolyte balance, muscle contraction, nerve impulse transmission||Table salt, processed foods, bread, meats||Muscle cramps, mental apathy, loss of appetite||Oedema, acute hypertension|
|Chloride||Fluid and electrolyte balance, stomach acid||Table salt, soy sauce, meats, milk, eggs, bread||Do not occur under normal physiology||Vomiting|
|Phosphorus||Bone and teeth mineralisation, cells, genetic material, blood clotting and blood pressure||All animal products||Muscular and bone weakness/pain||Calcification of tissues (kidneys)|
|Magnesium||Bone mineralisation, protein building, muscle contraction, immunity||Nuts, legumes, whole grains, dark green vegetables||Weakness, confusion, dysphagia||*From non-food sources only diarrhoea, alkalosis, dehydration|
Table 4. An overview of trace minerals.5
|Iron||Co-factor for cytochrome P450 reaction
Haemoglobin and myoglobin
|Red meat, legumes, green leafy vegetables||Iron deficiency anaemia||Haemochromatosis
|Copper||Co-factor in many reactions and part of some enzymes||Organ meats, shellfish, fish, nuts, whole grains, chocolate||Menkes disease
Abnormal hair growth
Delayed wound healing
Co-factor in many reactions
|Meat, seafood and poultry||Immune dysfunction
|Nausea, vomiting, diarrhoea
|Iodine||Thyroid hormone||Seaweed, fish, shellfish, iodised table salt, dairy, eggs||Hypothyroidism
|Selenium||Co-factor in peroxidase reactions||Brazil Nuts||Heart failure
Poor immune response
Nausea, vomiting, diarrhoea
|Sulphur||Key part of amino acids: methionine and cysteine||Cruciferous vegetables
|Brittle nails, hair loss, arthritis, nausea, vomiting, diarrhoea, skin rashes, cognitive impairment||Nausea, vomiting, diarrhoea
|Chromium||Component of glucose tolerance factors||Meat, grains, fruits, vegetables||Impairment in glucose tolerance and insulin sensitivity||Contact dermatitis
|Fluoride||Induction of bone formation
Prevents tooth enamel demineralisation
|Added to water||Dental caries
Iron deficiency is the most common nutritional disorder, affecting both industrialised and non-industrialised populations. It is estimated that over 2 billion people (30% of the world’s population), have iron deficiency anaemia. The causes of iron deficiency differ between age groups:
- Infants and children: high milk diets have no iron, yet also have high iron needs to support growth
- Women of childbearing age: menstruation and childbirth (increased blood loss)
- People over fifty: bowel cancer
- All age groups: diet
Symptoms of iron deficiency include fatigue, pallor, apathy, weakness and temperature intolerance.
Iron deficiency anaemia is the severe depletion of iron resulting in low haemoglobin and is rarer than iron deficiency.
Iron deficiency is correctable by addressing the cause, though supplements are often used to boost iron stores. An iron infusion can be used.
Dr Chris Jefferies
- Whitney E, Rolfes SR, Crowe T. Understanding Nutrition. 5th ed: Cengage Learning Australia; 2022.
- Pazirandeh S. Overview of water-soluble vitamins. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Available from: [LINK]
- Drezner MK. Patient education: Vitamin D deficiency (Beyond the Basics). In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Available from: [LINK]
- Med Libretexts (2020) 8.6: Major minerals, Medicine LibreTexts. Libretexts. Available from: [LINK]
- Pazirandeh S, Burns DL,Griffin IJ. Overview of dietary trace elements. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Available from: [LINK]
- Auerbach M. Causes and diagnosis of iron deficiency and iron deficiency anemia in adults. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Available from: [LINK]