JOURNAL OF AGRICULTURE AND BASIC SCIENCE

ISSN Online: 2518-4210

http://www.jabsjournal.com/

Full Length Review Article

Biological importance of vitamins for human health: A review
Muhammad Amir Maqbool1*, Muhammad Aslam1, Waseem Akbar2, Zubair Iqbal1
1
Plant Breeding and Genetics, University of Agriculture Faisalabad, Pakistan
2
Maize and Millets Research Institute (MMRI), Yousafwala, Sahiwal, Pakistan
*Corresponding author: amirmaqbool2269@gmail.com

Abstract
Vitamins are direly important for human health, growth, development, reproduction and maintenance,
and their deficiencies are imposing serious health hazards. Thirteen vitamins are true vitamins which are
further classified as water soluble and fat soluble vitamins. Vitamin A, E, K and D are fat soluble
vitamins whereas, vitamin B1, B2, B3, B5, B6, B9, B12, biotic and vitamin C are water soluble vitamins.
There are many other food components which have vitamin activity but these are not true vitamins.
There are wide range of dietary sources including both plant and animal sources for these vitamins. Their
regular dietary intake is essential for proper maintenance of health and development. Vitamin
deficiencies are causing the serious health problems, impairment of normal growth and development.
Basic introduction of vitamins, their biological importance, daily dietary requirement and dietary sources
for vitamins are discussed in this review article.
Keywords: Vitamin A, B complex, vitamin C, biotin, vitamin E, vitamin K
and these factors were designated with alphabet
Introduction letters. Alphabetizing became complicated due to
Vitamins are groups of highly complex different forms of vitamins (vitamin B complex),
compounds, organic in nature, present in foodstuffs differences in chemical structure within groups and
in traces, essential for normal metabolism and determination of chemical functions. Vitamins
absence of these nutrients cause disorders whereas, were also named based on their function and
resupply of these nutrients can cure the deficiency sources. Vitamin H was named to the factor which
symptoms (Marshall, 1986). Vitamins are diverse protects the haut, a German word meaning skin.
in nature relative to fats, carbohydrates and Vitamin K is derivative from Danish word
proteins. Vitamins are differentiated from other koagulation meaning coagulation. Pantothenic acid
groups by their organic nature and their derived from Greek word pantos, means found
classification depends on chemical nature and everywhere. Rules for nomenclature of vitamins
function. Very trace amounts of vitamins are were established by Committee on Nomenclature
needed for growth, development, health and of the American Institute of Nutrition (Cnain,
reproduction. Some vitamins are deviants from 1981).
usual definition and not always needed to be part of Human body is unable to synthesize the
food stuff i.e. ascorbic acid, vitamin D and niacin. vitamins so, their intake through diet is necessarily
Ascorbic acid is synthesized by animals, niacin vital. Vitamins are chemically complex compounds
synthesized from tryptophan amino acid and and have significant role in growth and
vitamin D synthesized from UV radiation from development of the human body. There are
sunlight. Therefore, specific species and under numerous vitamins like; vitamin A, vitamin C
certain conditions vitamin D, ascorbic acid and (ascorbic acid), vitamin D, vitamin E, vitamin B12
niacin does not fit in the definition of vitamins (cobalamin), vitamin B6, vitamin B5 (Pantothenic
(McDowell, 2000). So, far as classification of acid), vitamin B1 (thiamin), vitamin B3 (niacin),
vitamins is concerned, these are divided into two vitamin B2 (riboflavin) and vitamin B9 (folate,
main categories i.e. water soluble and fat soluble folic acid, or folacin), flavonoids (vitamin P).
vitamins. Vitamins of B complex and C are water Severe or even fatal diseases are caused by
soluble whereas, vitamin A, D, E, and K are fat deficiency of vitamins. Vitamin deficiencies are
soluble. Fat soluble vitamins have association with associated with specific disease like, vitamin A
fats and absorb with dietary fats. Absorption of fat associated with Blindness, vitamin B1 with
soluble vitamins follow the same mechanics as for beriberi, vitamin B3 with pellagra, vitamin B6 with
absorption of fats. Water soluble vitamins are not anemia, vitamin C with scurvy and vitamin D with
associated with fats and rendered unaffected by rickets (Asensi-Fabado and Munne´-Bosch, 2010).
alterations in fat absorption (McDowell, 2000; Biological importance of fat soluble and water
Wardlaw et al., 2004). soluble vitamins for human health is exclusively
In earlier days of vitamin discovery, discussed in this review article.
chemical composition of vitamins was unknown

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Fat soluble vitamins: vegetables, chili peppers, tomatoes, basil, papaya,

Vitamin A, D, E and K are the fat soluble shrimp, eggs, Brussels sprouts and grapefruit.
(Figure 1). Basic introduction of vitamins, Preformed vitamin A sources are shrimp,
biological importance, daily dietary intake and eggs, cow’s milk, cheese, yogurt, salmon, sardines,
dietary sources are descried for fat soluble chicken, turkey, tuna, cod, scallops, beef and lamb
vitamins. (WHFoods, 2017).

Vitamin D:
Introduction:
Vitamin D is very
important for human body but exact
intake dose is variable and has
inconsistent pattern because
exposure of sunlight also produce
vitamin D in human skin.
Ultraviolet B (UVB) wavelength of
sunlight strikes the body and
resultantly 7-dehydrocholesterol in
human body is converted into
cholecalciferol which is
preliminary form of vitamin D.
However, amount of cholecalciferol
produced by UV-B is unpredictable
due to type and nature of skin
pigments, skin health and nature of
sunlight. Cholecalciferol is not
fully active form of vitamin D but
Figure 1: Fat soluble vitamins there is involvement of kidney and livers for
conversion of cholecalciferol into active form of
vitamin D and these additional steps further make
the prediction difficult. Food sources are very
Vitamin A: limited which provide vitamin D but amount of this
Introduction:
vitamin in body can be increased by increasing the
Vitamin A is most complicated in nature.
exposure to sunlight (WHFoods, 2017).
It can be obtained both from plant and animal
Biological importance:
sources.Vitamin A from animal sources is known
Vitamin D is important for normal body
as retinoids whereas, from plant sources these are
functioning as its deficiency cause the
called provitamin A carotenoids. Retinol, retinal,
malformation and softening of bones. Vitamin D
retinoic acid and retinyl esters are different forms
deficiency is associated with many disorders like,
of retinoids. α-carotene, β-carotene and β-
osteoporosis, rickets, osteomalacia, loss of balance,
cryptoxanthin are the plant originated provitamin A
diabetes, rheumatoid arthritis, asthma, depression,
carotenoids which are converted into preformed
epilepsy and lowered immune function.
vitamin A retinoids during digestion in human
Malformation of bones in children is called rickets
body (WHFoods, 2017).
whereas, in adults it is called osteomalacia
Biological importance:
(Wagner and Greer, 2008). Vitamin D increases the
Vision, support, support to immune
calcium absorption from food and reduce the losses
system and inflammatory systems, cell growth and
through urine. It also maintains the blood calcium
development, antioxidant activity, promoting
level by pulling out the calcium from bones but this
proper cell communication (WHFoods, 2017).
option prevails only if there is sufficiently enough
Daily requirement:
vitamin D in foods. Vitamin D deficiency also
Daily intake requirement of vitamin A for
increase the risk of blood sugar level and diabetes
young males is 900 micrograms, for females 700
(Belenchia et al., 2013). Vitamin D is involved in
microgramsand for children 300-400 micrograms
maturation of white blood cells that is frontline for
(WHFoods, 2017).
immunity responses. Consistent association was
Dietary sources:
also identified between increased risk of respiratory
Provitamin A carotenoid sources are sweet
infection and vitamin D deficiency (Jolliffe et al.,
potato, carrots, spinach, kale, mustard greens,
2013). Vitamin D deficiency is reported to be
collard greens, turnip greens, Swiss chard, winter
increasing since 1980s due to increased use of
squash, Romaine lettuce, Bok Choy, cantaloupe,
sunscreens and decreased exposure to the sunlight
bell pepper, parsley, broccoli, asparagus, sea
(Faurschou et al., 2012).

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plants. K2 form is synthesized from K1 and K3

Daily requirement: form by bacteria and other microorganisms. In
Dietary intake should be 15 micrograms human body, K2 is also synthesized by biological
(600 International Unit) in daily basis for teenager conversion of K1 and K3. K2 is not present in
males and females (WHFoods, 2017). preformed form is plants but it is produced by
Dietary sources: fermenting bacteria through transformation of K1
Egg yolks,tuna, salmon, sardines, into K2 (Hirota et al., 2013). Key functions of
mushrooms, cow’s milk, soy milk, orange juice and vitamin K are photosynthesis, antioxidants and
fortified foods (WHFoods, 2017). energy generation by electron movement (Kurosu
and Begari, 2010). Scientific names for K1, K2 and
Vitamin E K3 are phylloquinones, menaquinones and
Introduction: menadiones respectively.
Vitamin E is a broad term which Biological importance:
comprised of four different tocopherols and four Blood clotting is beneficial or harmful
different tocotrienols. Collectively these eights depending upon the conditions of occurrence.
compounds are called "tocochromanols" and these Blood clotting is very complex process because
are fat soluble antioxidants. Alpha-tocopherol is there is involvement of twenty different proteins
well known and well-studied component of vitamin for completion of clotting process and four proteins
E. Being antioxidant, vitamin E protects the among them requires vitamin K for their activity
membrane fats from oxidative damage and (Shearer et al., 2012; Shearer, and Newman, 2014).
maintain the cellular functioning. This vitamin also In young person’s there is rare incidence
protects the food from oxidative damage during of vitamin K deficiency but frequent in newborns
storage and processing (WHFoods, 2017). because placenta prevent the extensive movement
Biological importance: of vitamin K to fetus. Severe gastrointestinal and
LDL (low-density lipoprotein) cholesterol liver diseases provoke the incidence of vitamin K
is protected by vitamin E from oxidative damage deficiency (Shearer et al., 2012; Shearer, and
caused by free radicals. Deficiency of vitamin E Newman, 2014).
make the LDL cholesterols prone to oxidative Vitamin K is important for bone health
damage and convert them into oxidized LDL. and its deficiency increases the risk of bone
Oxidized LDL accumulates in the blood vessels fracture. Experimentally it is proved that uptake of
and cause hardening of arteries known as vitamin K by bone cells is in the form of K1 and
atherosclerosis. Deficiency of vitamin E is also K2. Vitamin K is composed of prenyl repeating
associated with heart attack, cancer, stroke, units. K2 further consists of numerous subtypes
fibrocystic breast disease, epilepsy, PMS, diabetes, called MK-4, MK-5, MK-7, MK-8, and MK-9
parkinson's disease, cataract, alzheimer's disease, having 4,5,7,8, and 9 prenyl units. "M" in "MK"
intermittent claudication, cold sores, immune stands for "menaquinone" that is scientific name of
health and macular degeneration (WHFoods, K2 form whereas, "K" indicates the common name
2017). of vitamin K (Shearer et al., 2012; Shearer, and
Daily requirement: Newman, 2014).
Daily recommended intake of vitamin E is Osteoclasts are special type of the cells
15 milligrams for males and females of adult age involved in demineralization of bones and make the
while 5 milligrams for children (WHFoods, 2017). minerals available for other body functions but too
Dietary sources: much demineralization can harm the bones.
Vitamin E dietary sources are sunflower Vitamin K keeps the osteoclasts cells under
seeds, spinach, swiss chard, turnip greens, controls and induce the programmed cell death to
asparagus, beet greens, mustard greens, chili avoid the extensive production of osteoclast cells
peppers, almonds, broccoli, bell peppers, kale, and to keep the demineralization under control
tomatoes, avocado, peanut, shrimp, olives, olive (Atkins et al., 2009; Shearer, and Newman, 2014).
oil, collard greens, cranberries, raspberries, Under-carboxylatedosteocalcin is a
kiwifruit, carrots, green beans and leeks disorder in which risk of bone fracture is increased
(WHFoods, 2017). especially hip fracture. This disorder is caused by
lower carboxylation of osteocalcin protein. Vitamin
K especially K1 and K2, regulate the carboxylation
Vitamin K of osteocalcin proteins and strengthen the
Introduction: bones.Vitamin K is associated with blood clotting
Blood clotting factors are named as disorders, coronary artery disease, osteoporosis,
vitamin K because it is derived from German word liver disease, cancer, crohn's disease, celiac
“koagulation” which means blood clotting (Shearer disease, cystic fibrosis and ulcerative colitis
et al., 2012; Shearer, and Newman, 2014). K1, K2 (Shearer et al., 2012; Shearer and Newman, 2014).
and K3 are three basic types of vitamin K. K1 form
is most prevalent and needed for photosynthesis of

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Daily requirement: Vitamin-B1 (Thiamin)

Daily value for vitamin K intake is 80 Introduction:
micrograms. WHFoods recommended the 90 Vitamin B1 is the member of vitamin B
micrograms daily required intake for females and complex and also known as thiamin. Vitamin B1
120 micrograms for males while 55 micrograms for has important roles in human health. Vitamin B1
children (WHFoods, 2017). involves in the energy production from
Dietary sources: carbohydrates and fats (Kala and Prakash, 2003).
Specifically, food sources for K1 are dark
green leafy vegetables, for K2 are eggs, meat, fish, Biological importance:
dairy, fermented animal foods and fermented plant Importance of vitamin B1 can be realized
foods whereas, K3 is not naturally present in the with the fact that it acts as gate keeper among the
dietary foods (Shearer et al., 2012; Shearer, and carbohydrate breakdown (less energy step), Kreb
Newman, 2014). cycle (high energy step) and electron transport
Generally dietary sources for vitamin K chain. So, this vitamin is central in energy
are kale, spinach, mustard greens, collard greens, metabolism and its deficiency can seriously impair
beet greens, swiss chard, turnip greens, parsley, the energy metabolism. Deficiency of vitamin B1
broccoli, brussels sprouts, romaine lettuce, can seriously affect the nervous system, digestion
asparagus, basil, cabbage, bokchoy, celery, and heart. Brain is most energy demanding organ
kiwifruit, leeks, sage, green beans, cauliflower, of the body and resultantly severely impaired by
cucumber, tomatoes, oregano, black pepper, green vitamin B1 deficiency (Ba, 2008).
peas, blueberries, grapes, carrots, summer squash, Parkinson's, Alzheimer's and alcohol-
cloves, chili peppers, soybeans, avocado, related brain diseases are also linked with vitamin
raspberries, winter squash, pear, cranberries, bell B1 deficiency. Structure development and integrity
peppers, plum, cantaloupe and eggplant of brain cells are dependent on vitamin B1. In case
(WHFoods, 2017). of diabetes, gastrointestinal disease, heart failure
and elderly peoples, there is higher risk of vitamin
B1 deficiency (Keogh et al., 2012). Alcohol is
Water soluble vitamins inhibitor for the vitamin B1 nutrition as most of
Water soluble vitamins are vitamin B1, amount of this vitamin is used for detoxification of
B2, B3, B5, B6, B9, B12, Biotin and Vitamin C the alcohol. Different vitamins form a vitamin B
(Figure 2). basic information, biological complex have the overlapping functions and
importance, daily required amount and dietary supportive role for improving the functionality of
sources for these vitamins are discussed other members in complex. Diabetes, congestive
subsequently. heart failure, alzheimer's disease, beri-beri,
wernicke's encephalopathy,
liver failure, alcoholism,
pulmonary hypertension and
HIV/AIDS are the diseases
which are either cause or
effect of the vitamin B1
deficiency (WHFoods,
2017).
Daily requirement:
Daily intake requirement for
females is 1 milligram
whereas for males it is 1.2
milligram (WHFoods, 2017).
Dietary sources:
Thiamine dietary
sources are asparagus,
sunflower seeds, green peas,
flax seeds, Brussels sprouts,
beet greens, spinach,
cabbage, eggplant, romaine
Figure 2: Water Soluble vitamins lettuce, mushrooms, navy
beans, black beans, barley, dried peas, lentils, pinto
beans, lima beans, oats, sesame seeds, kidney
beans, peanuts, sweet potato, tofu, tuna, pineapple,
oranges, broccoli, green beans, onions, collard
greens, fortified cereals, dried beans, lean meats,

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soy foods and whole wheat grain (WHFoods, NADP and niacin containing enzymes are also
2017). quenchers of free radicals and protect the tissues
Vitamin-B2 (riboflavin) from oxidative damage. Vitamin B3 deficiency is
Introduction: also associated with alcoholism. Vitamin B3 is
This vitamin is also known as riboflavin associated with numerous diseases like, high
and higher level of B2 in urine turn it into yellow cholesterol, pellagra, osteoarthritis, reynaud's
color so, this is the only vitamin which provides us disease, acne vulgaris, schizophrenia and type-1
with visual clue of its abundance. Word flavinis diabetes (Lanska, 2010).
derived from Latin word flavus means yellow. Like Daily intake:
other B complex vitamins, this vitamin also Daily vitamin B3 requirement for males is
involves in energy metabolism (WHFoods, 2017). 16 milligrams whereas, for teenager females is 14
milligrams (WHFoods, 2017).
Biological importance:
Glutathione is most important antioxidant Dietary sources:
which provides antioxidative protection to body, Dietary sources for vitamin B3 aretuna,
and this antioxidant is recycled in the human body chicken, turkey, mushroom, salmon, lamb, beef,
by vitamin B2. This vitamin promotes iron asparagus, tomatoes, bell peepers, sardines,
metabolism and its deficiency also increase the risk peanuts, shrimps, brown rice, sweet potato,
of anemia as iron is important element for red sunflower seeds, barley, green peas, potatoes, cod,
blood cell production. Deficiency of this vitamin corn, carrots, cantaloupe, mushrooms, collard
increase the risk of migraine headache, iron greens, winter squash, brussels sprouts, summer
deficiency anemia, high homocysteine, congestive squash, spinach, broccoli, green beans, bokchoy,
heart failure, parkinson's disease, cataract and beet greens, soy sauce, kale, chili peppers, swiss
hypertension (WHFoods, 2017). chard, mustard greens, eggplant, turnip greens,
Daily requirement: cabbage, fennel, cauliflower, sea vegetables and
About 1.3 milligram for males and 1 parsley (WHFoods, 2017).
milligram vitamin B2 for females is needed on
daily basis (WHFoods, 2017). Vitamin-B5 (Pantothenic acid)
Dietary sources: Introduction:
Vitamin B2 dietary sources are spinach, Pantothenic acid is derived from Greek
beet greens, asparagus, sea vegetables, eggs, cow’s word “pantothen” which means "on all sides" or
milk, collard greens, broccoli, swiss chard, green "from all "quarters". Common presence of this
beans, mushrooms, bokchoy, turnip greens, kale, vitamin in foods is the reason for naming it as
mustard greens, bell peppers, soybeans, yogurt, pantothenic acid (WHFoods, 2017).
almonds, turkey, green peas, sweet potato, sardines, Biological importance:
tuna, winter squash, brussels sprouts, grapes, Use of carbohydrates, fats and proteins as
cabbage, carrots, summer squash, romaine lettuce, energy source is impaired, hormone production is
cauliflower, celery, chili peppers, lentils, peas, abandoned and immune system can collapse in case
dairy products, nuts and fortified cereals of pantothenic acid deficiency. Pantothenic acid is
(WHFoods, 2017). incorporated into Coenzyme A (CoA) which has
central position for energy metabolism. Deficiency
Vitamin-B3 (Niacin) of this vitamin is associated with acne vulgaris,
Introduction: chronic fatigue, high cholesterol and diabetes-
Vitamin B3 and Niacin are related foot ulcers (WHFoods, 2017).
interchangeable terms as niacin is the group of Daily requirement:
compounds having vitamin activity. Vitamin B3 Daily vitamin B5 requirement for human
comprised of nicotinic acid, nicotinamide and body is 10 milligrams. However daily intake
numerous enzymatic forms. Pellagra disease is requirement is also variable depending upon the
caused by deficiency of vitamin B3. Energy age, gender and health conditions of the individuals
production and antioxidative defense are the key (WHFoods, 2017).
functions of this vitamin for human health (Lanska, Dietary sources:
2010). Nicotinamide adenine dinucleotide (NAD) Dietary sources for vitamin B5 are
and nicotinamide adenine dinucleotide phosphate mushrooms, cauliflower, sweet potato, broccoli,
(NADP) are two distinct forms of vitamin B3 and beet greens, asparagus, turnip greens, bell peppers,
essentially involve in production of energy from cucumber, celery, avocado, lentils, dried peas,
dietary proteins, carbohydrates and fats (Leskova, chicken, turkey, yogurt, salmon, rye, beef, eggs,
2006). potatoes, wheat, corn, shrimps, papaya, winter
Biological importance: squash, cow’s milk, collard greens, raspberries,
Starch is synthesized from niacin and brussels sprouts, grapefruit, pineapple, watermelon,
stored in liver and muscles as energy source. NAD, carrots, oranges, swiss chard, spinach, summer

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squash, cabbage, fennel, mustard greens, tomatoes,

sea vegetables, romaine lettuce and bokchoy Daily requirement:
(WHFoods, 2017). Young males require 1.3 milligrams and young
females require 1.2 milligrams on daily basis
Vitamin-B6 (Pyridoxine) (WHFoods, 2017).
Introduction: Dietary sources:
This water soluble vitamin exists in Vitamin B6 dietary sources are tuna,
different forms i.e., pyridoxal (PL), pyridoxine spinach, cabbage, bokchoy, bell peppers, turnip
(PN), pyridoxal 5'-phosphate (PLP), pyridoxamine greens, garlic, cauliflower, turkey, beef, chicken,
(PM), pyridoxine-5'-phosphate (PNP) and salmon, sweet potato, potatoes, banana, winter
pyridoxamine 5'-phosphate (PMP) (WHFoods, squash, broccoli, brussels sprouts, collard greens,
2017). beet greens, kale, carrots, swiss chard, asparagus,
Biological importance: mustard greens, tomatoes, leeks, summer squash,
Functionally B6 is very important vitamin chili peppers, sunflower seeds, pinto beans,
as it is involved in red blood cell production, avocado, lentils, green peas, lima beans, onions,
carbohydrate metabolism, liver detoxification, shrimps, pineapple, cod, mushrooms, cantaloupe,
brain and nervous system health (Combs, 2007). corn, beets, eggplant, turmeric, green beans, celery,
Hemoglobin is oxygen career protein in blood and strawberries, watermelon, romaine lettuce, sea
its function is dependent on heme whereas, heme vegetables, spinach and fortified cereals
production is based on availability of vitamin B6. (WHFoods, 2017).
Vitamin B6 is also associated with rare types of
anemia known as sideroblasticanemias. Several Vitamin B9 (Folate)
steps of carbohydrate metabolism are governed by Introduction:
vitamin B6. Retrieval of glycogen from In last decade extensive research work
carbohydrate of cells is relying on this vitamin was done on folate and concluded that folates have
(Combs, 2007). critical importance for human health. There are
This vitamin is also involved in different forms of folates which are present in the
production of messaging molecules in brain and foods i.e., dihydrofolates, methylfolates,
nervous system, known as neurotransmitter. polyglutamylfolates and monoglutamylfolates
Dopamine, GABA and serotonin are key (Crider et al., 2011).
neurotransmitters whose biosynthesis is dependent Biological importance:
on vitamin B6. Interference in function of vitamin Well-known role of folates is to support
B6 through genetic mutation induces a rare and the brain health. Messengers molecules are
distinct type of condition known as pyridoxine- produced which are used by nerves to send the
dependent epilepsy. In this condition brain is under signals in whole body. BH4 cycle
developed and epileptic seizures are prevailing (tetrahydrobiopterin) revealed that there is close
during infancy (Combs, 2007; Gregory et al., association between folates and neurotransmitters
2013). especially serotonin and dopamine. BH4 and folates
Depressed mode is also found to be linked used same mechanism to cross the brain blood
with deficit intake of vitamin B6 however, this barrier. Folates support the cardiovascular system
association of depression and vitamin B6 is further and nervous system in human (Crider et al., 2011).
pronounced by folic acid deficiency. In recent Folates regulate the homocysteine level in
studies, vitamin B6 deficiency was also found to be blood and this amino acid is marker for
linked with attention deficit disorder. Liver cardiovascular diseases as higher level of
detoxification is accomplished by this vitamin and homocysteine showed the increased risk of
feeding the rats on pyridoxine-depleted foods cause cardiovascular diseases. Higher level of
the liver dysfunctioning (Gregory et al., 2013). homocysteine in blood is known as
Chronic inflammatory conditions appeared to be hyperhomocysteinemia whereas, optimum folates
linked with vitamin B6 deficiency. Metabolism of in blood especially in the form of 5-
tryptophan, other amino acids, proteins and methyltetrahydrofolate (5-MTHF) lower down the
development of immunity are also among the key level of homocysteine in blood so, it’s concluded
functions of this vitamin. Vitamin B6 deficiency that higher intake of folates can control the risk of
can provoke numerous diseases like, fibrocystic cardiovascular diseases (Hayden and Tyagi, 2004;
breast disease, premenstrual syndrome, carpal Crider et al., 2011).
tunnel syndrome, anemia, epilepsy, asthma, Balanced nitric oxide (NO) levels of blood
seborrheic dermatitis, morning sickness, is essential for regulation of cardiovascular health.
depression, high homocysteine and attention deficit NO plays important role in regulation of blood
syndrome (Combs, 2007; Gregory et al., 2013). pressure, blood flow and prevents clumping of
platelet cells. Nitric oxide synthase (NOS) enzyme
is involved in generation of NO with the help of

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BH4 (tetrahydrobiopterin). As BH4 regulate the • This vitamin is only synthesized by

functioning of NOS enzyme whereas, under microorganisms like bacteria and fungi.
insufficient availability of BH4, NOS impair the Mushroom, a fungus, have this vitamin.
cardiovascular health by producing free radical • This vitamin is difficult to absorb
superoxide. Dihydrofolatereductase (DHFR) • Daily intake requirement of this vitamin is
enzyme helps to keep the enough level of BH4 in very low.
the blood and convert folates into most bioactive • This vitamin contains heavy metal cobalt
form called tetrahydrofolate (THF). It is also that’s why it is also called cobalamin.
reported that folate is known as central nutrient for Biological importance:
cardiovascular health (Feng and Tollin, 2009; Besides these distinctions, this vitamin is also
Crider et al., 2011). very important for cardiovascular health of human.
Folate is important for production of red Vitamin B12 is involve in production of red blood
blood cells and its deficiency alongwith deficiency cells which are oxygen carrier throughout the blood
of copper, iron, vitamin B6 and vitamin B12 can stream with the help of hemoglobin pigment.
spoil the production of red blood cells. Folate Succinyl-CoA is the building block for hemoglobin
deficiency in females during pregnancy induced the and this building block is dependent on the vitamin
problems in neural tube which severely effects the B12. B12 deficiency anemia, is special type of
nervous system of fetus. Defects in neural tube can anemia caused by deficiency of vitamin B12.
also lead to the loss of pregnancy in females. Risk Vitamin B12 prevent the increase in level of
of cancer is also lowered in human by higher intake homocysteine. Higher blood homocysteine is
of folates, especially in females, risk of breast associated with numerous diseases like, peripheral
cancer is reduced. Deficiency of folate increases vascular disease, stroke and coronary heart disease.
the risk of depression, birth defects, high blood Actually, vitamin B12 converts homocysteine into
pressure, pregnancy, anemia, cancer prevention, methionine with the help of methionine synthase
gingivitis, ulcerative colitis, cognitive decline, enzyme to control the level of homocysteine
osteoporosis and psoriasis (Crider et al., 2011). (WHFoods, 2017).
Daily requirement: SAMe (S-adenosylmethionine) is also
Young males and females are requiring simultaneously recycled parallel of homocysteine
400 microgram folates on daily basis (WHFoods, conversion by vitamin B12. SAMe is known as
2017). universal donor of methyl group. Some
Dietary sources: neurotransmitters are dependent on
Dietary sources for folates are Lentils, methyltransferases enzymes for synthesis and these
asparagus, spinach, turnip greens, broccoli, beets, enzymes are dependent on methyl groups for
romaine lettuce, bokchoy, cauliflower, parsley, synthesis. So, methyl metabolism is another key
pinto beans, garbanzo beans, black beans, navy role imparted by vitamin B12 in brain health.
beans, kidney beans, papaya, Brussels sprouts, Vitamin B12 is necessary co-factor for
green peas, bell peppers, green beans, celery, DNA synthesis which is necessary molecule for
cabbage, summer squash, strawberries, tomatoes, every life. Vitamin B6, vitamin B9 and vitamin
leeks, fennel, lima beans, dried peas, avocado, B12 are necessarily needed for DNA synthesis.
peanuts, sunflower seeds, quinoa, winter squash, Division of blood cells is effected by deficiency of
oranges, cantaloupe, onions, collard greens, vitamin B12 which leads to production of
pineapple, raspberries, carrots, beet greens, abnormally large blood cells and this phenomenon
mushrooms, kiwifruit, kale, Swiss chard, is called macrocytosis (WHFoods, 2017).
mushrooms, basil, eggplant, mustard greens, Citric acid cycle is central cycle for
lemons, limes, orange juice, cereals and fortified aerobic energy production, whereas, succinyl-coA
bread (WHFoods, 2017). is key molecule in citric acid cycle. Vitamin B12
maintain the supply of succinyl-coA for citric acid,
Vitamin B12 (Cobalamin) so this vitamin has key role in aerobic energy
Introduction: metabolism. B12 also maintain the bone health as
Like other members of vitamin B incidence of osteoporosis is increased with
complex, B12 vitamin also plays important role in deficiency of this vitamin. Vitamin B12 deficiency
energy metabolism and other biological processes is associated with atrophic gastritis, pernicious
but differently from B complex vitamins, this has anemia, fatigue, neuropathy, tinnitus, migraine,
some unique functions (WHFoods, 2017) i.e. asthma, depression, memory loss, shingles,
• Vitamin B12 can be stored in body for mascular degeneration, alzheimer's disease, kidney
many years whereas, most of other B disease and multiple sclerosis (WHFoods, 2017).
vitamins can’t be stored for such a long Daily requirement:
time. Youngster either males or females needs 2.4
• It is larger molecule and has complex microgram vitamin B12 on daily basis (WHFoods,
structure 2017).

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 Biological Importance of vitamins for human health: A review / J. Agric. Basic Sci., Vol. 02, No. 03, 2017

Dietary sources: neurotransmitters is also dependent on this vitamin.

Dietary sources for vitamin B12 are These neurotransmitters involve in signaling of
sardines, salmon, tuna, cod, lamb, scallops, feelings, thoughts, and commands throughout brain
shrimps, beef, yogurt, cow’s milk, eggs, turkey, and nervous system. Vitamin C is also prerequisite
chicken, cheese, mushrooms and breakfast cereals for synthesis of serotonin, a hormone needed for
(WHFoods, 2017). proper functioning of endocrine system, nervous
system, digestive system and immune system.
Biotin (coenzyme R, vitamin H, and Serotonin is also involved in moods, experiences of
pain and stress, and daily body rhythms (sleep-
vitamin B7) wake cycles). In case of vitamin C deficiency, risk
Introduction: of scurvy, common cold, asthma, capillary
Previously this was known as coenzyme fragility, gout, gingivitis, musculoskeletal injury,
R, vitamin H, and vitamin B7 but now known as seasonal allergies and high blood pressure is
biotin, member of B-complex. Most importantly increased (WHFoods, 2017).
biotin plays a key role in sugar and fat metabolism Daily requirement:
(WHFoods, 2017). Dietary recommended intake for
Biological importance: youngster males and females are 75 milligrams on
Insulin, hormone that maintains sugar daily basis (WHFoods, 2017).
balance, production and functioning on cell are Dietary sources:
impaired due to deficiency of biotin. Skin rachesare Dietary sources for vitamin C are papaya,
also caused by biotin deficiency as this is needed bell peppers, broccoli, brussels sprouts,
for fat deposition in the skin. These fats are strawberries, pineapple, oranges, kiwifruit,
prerequisite for keeping the skin moist and supple cantaloupe, cauliflower, kale, cabbage, bokchoy,
whereas, in case of deficit fats, skin becomes grapefruit, parsley, turnip greens, beet greens,
irritated and flaky or scaly. Symptoms of cradle cap mustard greens, collard greens, raspberries, swiss
can be reduced in nursing infants by increasing chard, tomatoes, lemons and limes, spinach,
intake of biotin in food of lactating mothers. Skin asparagus, sea vegetables, fennel, sweet potatoes,
rash, cradle cap, seborrheic dermatitis, hair loss, winter squash, green peas, blueberries, cranberries,
diabetes, brittle nails, pregnancy issues and watermelon, green beans, summer squash, carrots,
seizures are the problems associated with plum, garlic, basil, dill, romaine lettuce, potatoes,
deficiency of this vitamin (WHFoods, 2017). avocado, onions, banana, apple, pear, beets, leeks,
Daily requirement: apricot, celery, cucumber and peppermint
Daily intake value is 30 micrograms biotin (WHFoods, 2017).
for males and females (WHFoods, 2017).
Dietary sources:
Biotin dietary sources are tomatoes, References
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