Submit manuscript...
Advances in
eISSN: 2378-3168

Obesity, Weight Management & Control

Mini Review Volume 6 Issue 2

Biochemical functions of micronutrients

Gulcin Sagdicoglu Celep,1 Pinar Kaynar,2 Reza Rastmanesh3

1Department of Family and Consumer Sciences Education, Gazi University, Turkey
2Institution of Public Health of Turkey, Turkey
3Nutritionist, Iran

Correspondence: Reza Rastmanesh, Nutritionist, Independent Researcher, Tehran, Iran

Received: October 28, 2016 | Published: January 27, 2017

Citation: Celep GS, Kaynar P, Rastmanesh R. Biochemical functions of micronutrients. Adv Obes Weight Manag Control. 2017;6(2):43-45. DOI: 10.15406/aowmc.2017.06.00147

Download PDF


Micronutrients are vitamins and minerals required in small amounts that are essential for healthy development and growth. They have great importance for a healthy living.1 Micronutrients play a central part in metabolism and in the maintenance of tissue function.2

Vitamins are organic substances that function as regulators in the body. They are divided into two groups: fat soluble vitamins (vitamin A, D, E and K) and water soluble vitamins (Vitamin B1, B2, B6, B12, Vit C, Folic acid, etc.).3,4 Fat soluble vitamins are stored in the fat tissues and liver, water solube vitamins are found in the aqueous parts of the cells, inside the compartments such as mitochondria which is responsible for oxidation of carbohydrates and fats for energy.5 There are many benefits of vitamins and they have a major impact on our overall health.

Minerals are essential nutrients that represent about 5-6% of the total body weight. There are two major groups of minerals depending on the percentage of body weight and the amount required in diet. Major or macro-minerals are present in the body at levels greater than 0.01% and they are required in the body in amounts greater than 100 mg/day. They function in both structural and regulatory roles. Some of the major minerals include calcium, phosphorus, sodium, potassium, magnesium and chloride. Trace or micro-minerals are present in the body at levels less than 0.01% and they are required in amounts less than 50 mg/day, therefore they function primarily in regulatory roles.5 Trace elements include iron, cobalt, chromium, copper, fluordie, iodine, manganese,selenium, zinc and molybdenum. They are importantant in many metabolic events and also for healthy immune functions.

Although micronutrients are found naturally in a variety of plant and animal based foods, they can be synthesized in the laboratory that are used in fortified foods.6 Micronutrients are important for human body because they are required for vital processes in the human body and their deficiencies can cause serious health problems.7

The World Health Organization (WHO) has reported that more than 2 billion people in the world today suffer from micronutrient deficiencies caused largely by dietary deficiencies of vitamins and minerals, primarily iodine, iron, vitamin A, vitamin D and zinc, with important health consequences.8 The importance of these deficiencies for the public health lies upon their magnitude and their health consequences, especially in pregnant women and young children, as they might affect fetal and child growth, cognitive development and resistance to infections.

 Micronutrient deficiencies are globally important problems which are not always clinically apparent or dependent on food supply and consumption patterns. They might be associated with physiologic effects that can be lifethreatening or more commonly damaging to optimal health and functions of the body.8 Iron deficiency is the most prevalent nutrition problem in the world.8

Other than a low dietary intake, important causes of maternal near miss (MNM) include poor bioavailability from foods (especially for minerals), frequent infection with parasites, diarrhea, and various malabsorption disorders. The presence of any of these risk factors can lead to an underestimation of the prevalence of deficiency in a population if this is calculated on the basis of micronutrient intakes alone.

Biochemical functions of micronutrients are reported as follows9

  1. Cofactors in metabolism-trace elements are frequently involved in modulating enzyme activity or are an integral part of enzyme prosthetic groups.
  2. Coenzymes in metabolism-many vitamins or metabolites of vitamins are required to play an active part within complex biochemical reactions. These reactions are critical to intermediary metabolism and ensure utilisation of the major nutrients to provide energy, proteins and nucleic acids.
  3. Genetic control-zinc “fingers” are transcription control factors that bind to DNA and regulate transcription of receptors for steroid hormones and other factors.
  4. Antioxidants-much of the popular interest in the micronutrients stems from the recognition that many of the micronutrients have antioxidant properties.

Deficiency conditions, their worldwide prevalence and toxicity of some important micronutrients are presented in Table 1.



Deficiency Prevalence



Anaemia; low levels of haemoglobin,
ferritin reduced learning and work capacity,
increased maternal and infant mortality,
low birth weight

2 billion

Bloody diarrhoea, vomiting, sometimes liver failure


Poor growth and sexual maturation,
anaemia, enlarged liver and spleen,
skin rash, lethargy pregnancy outcome,
impaired growth (stunting),
genetic disorders, decreased resistance to
infectious diseases

Estimated high in developing countries

Nausea, vomiting, epigastric pain,
abdominal cramps, diarrhoea, central nervous system deficits,
copper deficiency


Mottling of teeth; fluorosis Increased
dental decay, affects bone health


Excess tooth decay


Goiter, hypothyroidism, iodine
deficiency disorders, increased risk of stillbirth,
birth defects infant mortality, cognitive impairment

2 billion at risk



Decreased bone mineralization,
rickets, osteoporosis

Insufficient data, estimated to be widespread



Fragile red cells; cardiomyopathy,
heart and skeletal muscle degeneration, cardiovascular
risk and increased cancer

Insufficient data, common in Asia, Scandinavia, Siberia

Neuromusculer defects; liver and muscle damage


Anaemia; poor wound healing;
lethargy; depressed collagen synthesis

Insufficient data, estimated to be widespread


Vitamin A

Night blindness, xerophthalmia,
increased risk of mortality in children and pregnant women

254 million preschool children

Hypervitaminosis A

Folate (vitamin B9)

Megaloblastic anemia,
neural tube and other birth defects,
heart disease, stroke, impaired cognitive function, depression

Insufficient data


Cobolamine (vitamin B12)

Megaloblastic anemia (associated with
Helicobacter pylori induced gastric atrophy

Insufficient data


Thiamine (viamin B1)

Beriberi (cardiac and neurologic),
Wernicke and Korsakov syndromes
(alcoholic confusion and paralysis)

Insufficient data,
estimated as common in developing countries
and in famines, displaced persons


Vitamin D

Rickets, osteomalacia,
osteoporosis, colo rectal cancer

Widespread in all age groups,
low exposure to ultra violet rays of sun

Bone demineralization,
Soft Tissue Calcifications

Vitamin B6 (pyridoxine)

Dermatitis, neurological disorders,
convulsions, anemia, elevated
plasma homocysteine

Insufficient data,
estimated as common in developing countries
and in famines, displaced persons


Riboflavin (Vitamin B2)

Non specific – fatigue, eye changes,
dermatitis, brain dysfunction,
impaired iron absorption

Insufficient data, est.
to be commonin developing countries


Table 1 Deficiency conditions, their worldwire prevalence and toxicity of some important micronutrients

It was reported that adequate intakes of most micronutrients can be obtained from a typical diet in the UK in adults.10-13 Daily recommended intake values for vitamins and minerals for adults are presented in Table 2 & 3 respectively.


Food Sources

Daily Value

Thiamin (Vit B1)

Whole grains, seeds, nuts, legumes, fortified foods

1.1-1.2 mg

Riboflavin (Vit B2)

Liver, dairy products, whole grains, leafy greens, meat, eggs

1.1-1.3 mg

Niacin (Vit B3)

Meat, legumes, peanut, can be made from tryptophan

14-16 mg NE

Pantothenic acid (B5)

Meat, legumes, whole grains, widespread in food

5 mg

Vit B6

Meat, fish, poultry, legumes, whole grains, nuts, seeds

1.3-1.7 mg

Vit B12

Animal products, liver, mussel

2.4 µg

Vit C

Citrus fruits, green peppers, strawberries, rosehip, parsley

75-90 mg


Liver, egg yolk, synthesized in the gut

30 µg

Folic acid

Leafy green vegetables, legumes

400 µg

Vit A

Liver, butter, eggs, carrots, leafy greens, cantaloupe

700-900 µg

Vit D

Egg yolk, liver, tuna, somon, synthesis from sunlight

5-15 µg

Vit E

Vegetable oils, leafy greens, seeds, nuts

15 mg

Vit K

Synthesis by intestinal bacteria, vegetable oils, leafy greens

90-120 µg

Table 2 Recommended Vitamin Intake for Adults.

NF: Niacin equivalent2,9


Food Sources

Daily Value


Table salt, processed foods, meat, seafood

1500 mg


Fresh fruits, vegetables, potato, banana, meat, nuts, whole grains

4700 mg


Table salt, processed foods

2300 mg


Milk, cheese, yoghurt, fish, leafy green vegetables, meat

1000-1200 mg


Meat, liver, diary, cereals, nuts

700 mg


Green vegetables, whole grains, nuts, seeds

310-420 mg

Trace Elements


Red meat, green vegetables, whole grains, egg yolk, apricot

8-18 mg


Organ meats, nuts, seafood, cocoa, whole grains, Glycyrrhiza glabra

900 µg


Meat, seafood, oyster, wholegrains, eggs, nuts

8-11 mg


Organ meats, liver, seafood, eggs, whole grains

55 µg


Iodized salt, fish, seafood, dairy products

150 µg


Brewers yeast, nuts, whole grains, mushrooms, black pepper

25-35 µg


Drinking water, tea, fish, toohpastes

3-4 mg


Legumes, whole grains, tea, nuts, apricot, coffee

1.8-2.3 mg


Eggs, organ meat, milk, legumes

45 µg

Table 3 Recommended Major Minerals Intake for Adults2,9

Clinical benefits can be obtained by supplementation of micronutrients for individuals who are severely depleted however regarding to the micrograms to milligrams ranges of their daily intake values, excess amounts can be even harmful. Consequently, it is recommended to consume micronutrients in proper amounts to balance the adequate levels for optimum health.



Conflict of interest

Author declares that there is no conflict of interest.


Creative Commons Attribution License

©2017 Celep, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.