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Magnesium Magnesium is required for essential cellular activities that support
various physiological functions. It is involved in several enzymatic reactions including glycolysis, fat and protein metabolism, and adenosine triphosphate hydrolysis in
which food is metabolized and new products are formed (Shils 1998). It also serves
as a physiologic regulator of membrane stability and neuromuscular, cardiovascular, immune, and hormonal functions. Dietary restriction of magnesium and its deficiency results in reduced magnesium status, and impaired physiologic function and
performance in untrained adults (Lukaski 2004). Green, leafy vegetables and unprocessed grains are the dietary sources of magnesium. Some water sources have also
been reported to be good sources of magnesium (Lukaski 1995; Gibney et al. 2009).
Iron Iron is an essential element in living organisms as it plays a vital role in oxygen transport, DNA synthesis, and electron transport in various metabolic processes.
Its deficiency and overload can lead to anameia, and other neurodegenerative
diseases. The body requires iron for the synthesis of its oxygen transport proteins
e.g. haemoglobin and myoglobin and for the formation of heme and other iron–containing enzymes involved in electron transfer and oxidation–reductions (Abbaspour
et al. 2014). It is important for growth, healthy immune system and for energy production. In cellular respiration, it functions as essential component of enzymes
involved in biological oxidation (Malhotra 1998). There are two forms of iron:
heme iron and non–heme iron. The heme iron is highly bioavailable and is found in
animal products (red meat, fish, and poultry) and in some vegetable products (beans,
nuts, and dried fruit), whole grains, fortified breakfast cereals, soybean flour and
most dark green leafy vegetables (Arinola 2008). The heme iron content in food
from animal source is about 40% of the total iron. Whereas, red meat provides more
heme iron than white fish. Non–heme iron is less bioavailable and is found mostly
in plant–based foods and makes up the remaining estimated 60% of iron found in
animal products (Schönfeldt et al. 2016). Iron compounds recommended for food
fortification include ferrous sulfate, ferrous fumerate, ferric pyrophosphate, and
electrolyte iron powder.
Selenium Selenium is of fundamental importance to human health as it is required
by the body in small amounts for proper functioning of the immune system. Its
deficiency occurs when the body does not get enough mineral. The main functions
of Se are in enzymatic activity, reducing the risk of coronary heart disease (CHD)
through its antioxidant effect (WHO/FAO 2004a; Brown and Arthur 2001) and protecting against prostate cancer (Clark et al. 1998; Khokhar et al. 2012). It is associated with the protection of body tissues against oxidative stress and infection, and
modulation of growth and development. Approximately 30, 15, 30, and 10 % of
tissue selenium is located in liver, kidney, muscle, and blood plasma, respectively.
The tissue selenium is present in proteins as seleno–analogues of sulfur amino
acids. Other metabolically active forms of selenium include seleno trisulphides and
acid–labile selenium compounds. The selenoenzyme thioredoxin reductase is
involved in disposal of the products of oxidative metabolism (Howie et al. 1998). It
contains two selenocysteine groups per molecule and is a major component of a
redox system, having the capacity to scavenge toxic concentrations of peroxides
K. Sharma et al.
Magnesium Magnesium is required for essential cellular activities that support
various physiological functions. It is involved in several enzymatic reactions including glycolysis, fat and protein metabolism, and adenosine triphosphate hydrolysis in
which food is metabolized and new products are formed (Shils 1998). It also serves
as a physiologic regulator of membrane stability and neuromuscular, cardiovascular, immune, and hormonal functions. Dietary restriction of magnesium and its deficiency results in reduced magnesium status, and impaired physiologic function and
performance in untrained adults (Lukaski 2004). Green, leafy vegetables and unprocessed grains are the dietary sources of magnesium. Some water sources have also
been reported to be good sources of magnesium (Lukaski 1995; Gibney et al. 2009).
Iron Iron is an essential element in living organisms as it plays a vital role in oxygen transport, DNA synthesis, and electron transport in various metabolic processes.
Its deficiency and overload can lead to anameia, and other neurodegenerative
diseases. The body requires iron for the synthesis of its oxygen transport proteins
e.g. haemoglobin and myoglobin and for the formation of heme and other iron–containing enzymes involved in electron transfer and oxidation–reductions (Abbaspour
et al. 2014). It is important for growth, healthy immune system and for energy production. In cellular respiration, it functions as essential component of enzymes
involved in biological oxidation (Malhotra 1998). There are two forms of iron:
heme iron and non–heme iron. The heme iron is highly bioavailable and is found in
animal products (red meat, fish, and poultry) and in some vegetable products (beans,
nuts, and dried fruit), whole grains, fortified breakfast cereals, soybean flour and
most dark green leafy vegetables (Arinola 2008). The heme iron content in food
from animal source is about 40% of the total iron. Whereas, red meat provides more
heme iron than white fish. Non–heme iron is less bioavailable and is found mostly
in plant–based foods and makes up the remaining estimated 60% of iron found in
animal products (Schönfeldt et al. 2016). Iron compounds recommended for food
fortification include ferrous sulfate, ferrous fumerate, ferric pyrophosphate, and
electrolyte iron powder.
Selenium Selenium is of fundamental importance to human health as it is required
by the body in small amounts for proper functioning of the immune system. Its
deficiency occurs when the body does not get enough mineral. The main functions
of Se are in enzymatic activity, reducing the risk of coronary heart disease (CHD)
through its antioxidant effect (WHO/FAO 2004a; Brown and Arthur 2001) and protecting against prostate cancer (Clark et al. 1998; Khokhar et al. 2012). It is associated with the protection of body tissues against oxidative stress and infection, and
modulation of growth and development. Approximately 30, 15, 30, and 10 % of
tissue selenium is located in liver, kidney, muscle, and blood plasma, respectively.
The tissue selenium is present in proteins as seleno–analogues of sulfur amino
acids. Other metabolically active forms of selenium include seleno trisulphides and
acid–labile selenium compounds. The selenoenzyme thioredoxin reductase is
involved in disposal of the products of oxidative metabolism (Howie et al. 1998). It
contains two selenocysteine groups per molecule and is a major component of a
redox system, having the capacity to scavenge toxic concentrations of peroxides
K. Sharma et al.