567
wide variety of food mainly in dark leafy vegetables, fruits, and animal products
(Gibney et al. 2009; Mahan and Raymond 2016; Titchenal et al. 2018) poultry,
shellfish, salmon, tuna, whole grains, wheat germ, beans, soybeans, beets, dark
leafy greens, orange juice, citrus fruits, cantaloupes, avocado, asparagus, milk, etc.
Vitamin B 12 (Cobalamin) Cobalamin is a water–soluble vitamin that contains a
cobalt metal ion. It is needed for nerve tissue health, brain function, and the production of red blood cells. It is necessary for metabolism of every cell of the human
body, mainly influencing DNA synthesis, fatty acid, and amino acid metabolism for
folate coenzyme function, and in hemoglobin synthesis. Vitamin B 12 benefits CNS
in many important ways. It maintains health of nerve cells, and helps to form the
protective covering of nerve (myelin sheath) for smooth functioning of the nervous
system. It is also involved in B–cell synthesis and T–cell multiplication of lymphocyte (WBC) to strengthen bones and immune system (Sakane et al. 1982). Vitamin
B 12 deficiency causes macrocytic anemia in children and adults. There is an increased
risk for neural–tube defects in babies born to cobalamin–deficient mothers. Lower
Vitamin B 12 levels cause a reduction in RBC formation and prevent them from
proper development. Other deficiency symptoms include sore mouth or tongue,
weight loss, pale skin, diarrhea, and menstrual problems. B 12 deficiency also renders
people more susceptible to other infections (Gibney et al. 2009; Huskisson et al.
2007). Vitamin B 12 cannot be synthesized naturally in humans and plants but present
naturally in animal products such as fish, meat, poultry, eggs, and milk products.
Vitamin C (Ascorbic Acid) Commonly known as the L–ascorbic acid, vitamin C
is essential in the diet for humans, although most other mammals can readily synthesize it. It is found in almost every type of body tissue but is present in higher
concentrations in pituitary gland and central nervous system (Huskisson et al.
2007). It stimulates absorption of iron from the intestine and modulates transportation of iron for storage. It is involved in cellular growth and differentiation, collagen
formation, and in the formation of catecholamine and carnitine (Kraemer et al.
2012). In the brain it aids in natural synthesis of vital neurotransmitters like dopamine and noradrenalin (Huskisson et al. 2007). Ability of vitamin C to easily donate
electrons makes it a highly effective antioxidant. It neutralizes and removes reactive
oxygen species (ROS) formed in immune cells which would lead to the destruction
of immune cells (Maggini et al. 2007). Vitamin C actively takes part in warding off
the infectious agents during an infection (Hume and Weyers 1973). It protects lipids
both by scavenging free radicals and by aiding in the regeneration of vitamin E. It
boosts up human immunity towards infections and cold illnesses by increasing
phagocytosis, lymphocyte proliferation and neutrophil chemotaxis against
exogenous pathogens. Vitamin C deficiency causes scurvy, the signs and symptoms
include skin disorders, bleeding gums, painful joints, weakness, depression, and
increased susceptibility to infections. It can be prevented by the intake of vitamin C
rich fruits and vegetables. Higher intake of vitamin C reduces the risk of gout which
is caused by elevated levels of uric acid characterized by recurrent attacks of tender,
25 Bioavailability of Nutrients and Safety Measurements
wide variety of food mainly in dark leafy vegetables, fruits, and animal products
(Gibney et al. 2009; Mahan and Raymond 2016; Titchenal et al. 2018) poultry,
shellfish, salmon, tuna, whole grains, wheat germ, beans, soybeans, beets, dark
leafy greens, orange juice, citrus fruits, cantaloupes, avocado, asparagus, milk, etc.
Vitamin B 12 (Cobalamin) Cobalamin is a water–soluble vitamin that contains a
cobalt metal ion. It is needed for nerve tissue health, brain function, and the production of red blood cells. It is necessary for metabolism of every cell of the human
body, mainly influencing DNA synthesis, fatty acid, and amino acid metabolism for
folate coenzyme function, and in hemoglobin synthesis. Vitamin B 12 benefits CNS
in many important ways. It maintains health of nerve cells, and helps to form the
protective covering of nerve (myelin sheath) for smooth functioning of the nervous
system. It is also involved in B–cell synthesis and T–cell multiplication of lymphocyte (WBC) to strengthen bones and immune system (Sakane et al. 1982). Vitamin
B 12 deficiency causes macrocytic anemia in children and adults. There is an increased
risk for neural–tube defects in babies born to cobalamin–deficient mothers. Lower
Vitamin B 12 levels cause a reduction in RBC formation and prevent them from
proper development. Other deficiency symptoms include sore mouth or tongue,
weight loss, pale skin, diarrhea, and menstrual problems. B 12 deficiency also renders
people more susceptible to other infections (Gibney et al. 2009; Huskisson et al.
2007). Vitamin B 12 cannot be synthesized naturally in humans and plants but present
naturally in animal products such as fish, meat, poultry, eggs, and milk products.
Vitamin C (Ascorbic Acid) Commonly known as the L–ascorbic acid, vitamin C
is essential in the diet for humans, although most other mammals can readily synthesize it. It is found in almost every type of body tissue but is present in higher
concentrations in pituitary gland and central nervous system (Huskisson et al.
2007). It stimulates absorption of iron from the intestine and modulates transportation of iron for storage. It is involved in cellular growth and differentiation, collagen
formation, and in the formation of catecholamine and carnitine (Kraemer et al.
2012). In the brain it aids in natural synthesis of vital neurotransmitters like dopamine and noradrenalin (Huskisson et al. 2007). Ability of vitamin C to easily donate
electrons makes it a highly effective antioxidant. It neutralizes and removes reactive
oxygen species (ROS) formed in immune cells which would lead to the destruction
of immune cells (Maggini et al. 2007). Vitamin C actively takes part in warding off
the infectious agents during an infection (Hume and Weyers 1973). It protects lipids
both by scavenging free radicals and by aiding in the regeneration of vitamin E. It
boosts up human immunity towards infections and cold illnesses by increasing
phagocytosis, lymphocyte proliferation and neutrophil chemotaxis against
exogenous pathogens. Vitamin C deficiency causes scurvy, the signs and symptoms
include skin disorders, bleeding gums, painful joints, weakness, depression, and
increased susceptibility to infections. It can be prevented by the intake of vitamin C
rich fruits and vegetables. Higher intake of vitamin C reduces the risk of gout which
is caused by elevated levels of uric acid characterized by recurrent attacks of tender,
25 Bioavailability of Nutrients and Safety Measurements