2. What is a Vitamin?
Vitamin is a naturally occurring organic
molecule that is a normal constituent of
diet.
It should be essential and required only
in minute amounts.
And, it is required to maintain the
normal cellular, biochemical and tissue
integrity.
3. Properties of vitamin
Vitamins Are Naturally Occurring.
But sometimes synthetic compound shows greater
activity such as L- ascorbic acid is twice potent than
naturally occurring racemic mixtures. Same as S-
Biotin, D-Pantothenic acids.
Vitamins Are Essential Because They are Not
Produced by Human Biochemical Pathways.
With two exceptions, such as niacin which is derived
from conversion of an essential amino acid
tryptophan. Vit D3- cholecalciferol also occurs by
photochemical reaction on skin from 7-
dehydrocholesterol.
4. Properties of vitamin
Vitamins are organic in nature.
Trace elements such as Zinc, Iron, Magnesium,
Manganese, Chromium, Selenium are not called
vitamins.
Vitamins Are normal constituent of diet
Exception is cholecalciferol but some of the world
populations get it from protein of marine sources. Rest
of the population get it from direct sunlight effects on
cholesterol.
5. Properties of vitamin
Vitamins Are required in minute amounts.
This is arbitrary, but ranges from 2.0 µg for cyanocobalamin to 90
mg for ascorbic acid.
Vitamins Are Required to Maintain Normal Biochemical
Functions of the Tissues.
Either as a hormone or chemical messenger (cholecalciferol),
structural component in some metabolic process (pantothenic
acid), or a coenzyme (phytomenadione, thiamine, riboflavin,
niacin, pyridoxine, biotin, folic acid, cyanocobalamin).
Some vitamins have more than one biochemical role. E.g.Vitamin
A as an aldehyde (retinal) is a structural component of the visual
pigment rhodopsin and, in its acid form (retinoic acid), is a
regulator of cell differentiation.
6. Causes of vitamin deficiencies
Inadequate ingestion due to poor diet
Economic deprivation
Self imposed reducing diet
Diseases (loss of appetite due to chemotherapy, depression)
Inadequate absorption
Disease at GIT (Crohn’s disease, parasites)
Mineral oil laxatives (Vit A, D, E, K removes)
Ion exchange resins ingestion (colestipol,
colestyramine)
Cystic fibrosis causes less secretion of lipase enzyme
7. Causes of vitamin deficiencies
Inadequate utilization
Genetic diseases
Drug-vitamin reactions (isoniazid- pyridoxine, phenobarbitol-
cholecalciferol, methotrexate-folic acid)
Increased requirements of RDA(Recommended
Dietary Allowance)
Increased physical activity
Medical needs (severe burns, illness, surgery,
malignancies, pregnancy)
Chronic intake of alcohol
Ethyl alcohol interferes the uptake, processing, and storage of
folic acid and thiamine.
8. Classification
Thiamine was the first vitamin (B1) whose
structure was elucidated. It is an amine
leading to the term vital amine and finally
vitamin.
9. Classification
Fat soluble vitamins
Vitamin A, D, E and K
Found in the fats and oils of food.
Absorbed into the lymph and carried in
blood with protein transporters =
chylomicrons.
*Stored in liver and body fat and can
become toxic if large amounts are
consumed.
10. Classification
Water soluble vitamins
Vitamin B and C
Found in vegetables, fruit and grains, meat.
Absorbed directly into the blood stream
Not stored in the body and toxicity is rare.
Alcohol can increase elimination and
smoking can cause decreased absorption.
12. Vit RDA Deficiency
Upper
intake overdose
Vit A 900 µg
Night-blindness,
Hyperkeratosis 3,000 µgHypervitaminosis A
Vit B1 1.2 mg Beriberi N/D
Drowsiness or muscle
relaxation
Vit B2 1.3 mg Ariboflavinosis N/D
Vit B3 16.0 mg Pellagra 35.0 mg
Liver damage (doses >
2g/day)
Vit B5 5.0 mg Paresthesia N/D
Diarrhea, nausea and
heartburn.
Vit B6
1.3–
1.7 mg
Anemia, peripheral
neuropathy. 100 mg
nerve damage (>
100 mg/day)
Vit B7 30.0 µg Dermatitis, enteritis N/D
13. Vit RDA Deficiency
Upper
intake overdose
Vit B9 400 µg
Megaloblast, neural
tube defects 1,000 µg
Vit B12 2.4 µg Megaloblastic anemia N/D Acne-like rash
Vit C 90 mg Scurvy 2,000 mg
Vitamin C
megadosage
Vit D 10 µg Rickets, Osteomalacia 50 µg Hypervitaminosis D
Vit E 15 mg
Mild hemolytic
anemia 1,000 mg
Increased congestive
heart failure
Vit K 120 µg Bleeding diathesis N/D Increases coagulation
14. Fat Soluble Vitamins
Vitamin A (precursor – beta carotene)
3 forms: retinol (stored in liver), retinal, retinoic acid
Roles in body:
Regulation of gene expression
Retinol, a part of the visual pigment rhodopsin, maintains
clarity of cornea
Required for cell growth and division - epithelial cells,
bones and teeth
Promotes development of immune cells, especially
“Natural Killer Cells”
Antioxidant
Retinoic acid is required for the development of goblet
mucous cells.
15.
16.
17.
18. Fat Soluble Vitamins
Vitamin A
Deficiencies cause:
Night blindness, xerophthalmia (keratin deposits
in cornea), macular degeneration.
Skin and mucous membrane dryness and
infection, keratin deposits.
Anemia
Developmental defects – bones, teeth, immune
system, vision
19. Fat Soluble Vitamins
Vitamin A
Toxicities (single large doses of
supplements, eating excessive amounts of
liver) cause:
Fragile RBCs, hemorrhage
Bone pain, fractures
Abdominal pain and diarrhea
Blurred vision
Dry skin
Liver enlargement
20. Fat Soluble Vitamins: A
Hypervitaminosis A
fatigue, malaise, lethargy, abdominal comfort,
bone and joint pain, severe headache,
insomnia, restlessness, dry and scaly skin,
loss of body hair, brittle nails, constipation, and
irregular menses.
Depending on the health of person's liver,
there is risk of developing cirrhosis. There is a
daily Tolerable Upper intake Level (UL) of
3000 µg for this vitamin.
21. Fat Soluble Vitamin A: Drugs
Due to retinol deficiency results in
keratinization of epithelial tissue, so retinol
was recommended for skin conditions
including acne.
That is not proved yet but active form retinoic
acid is targeted for treating acne, psoriasis and
malignancy.
Retinoid and Retinoid-like Drugs Used in
the Treatment of Acne
22. Fat Soluble Vitamin A: Retinoids
The first product introduced was tretinoin, which is a
topical all-trans retinoic acid. It produces a complex
response related to increasing the turnover of follicular
epithelial cells. The result is decreased cohesiveness
of follicular epithelial cells.
Tretinoin is also used as an antiwrinkle cream. There
is an increase in epidermal cell turnover, shedding
older cells and thickening the skin. Also the drug may
combine with epidermal retinoic acid receptors,
thereby decreasing keratin production. Keratin can
contribute to skin wrinkling.
23. Fat Soluble Vitamin A: Adapalene
Although used topically, the nonretinoid,adapalene, a
third generation drug, does bind to the retinoic acid
nuclear receptor and does affect cell differentiation,
keratinization, and inflammatory responses.
It is approved in 1996 by FDA for treatment of Acne.
Available form is 0.1% cream and gel, 0.3% gel.
Unlike tretinoin, adapalene has also been shown to
retain its efficacy when applied at the same time
as benzoyl peroxide due to its more stable chemical
structure.
26. Fat Soluble Vitamin D
Vitamin D – precursor is cholesterol, converted by UV
from sunlight exposure, therefore is a “non-essential”
vitamin.
Cholecalciferol is produced in the body from
endogenously synthesized 7-dehydrocholesterol.
Excess amounts of cholecalciferol can result in excess
calcium uptake from the intestinal tract, leading to
calcification of soft tissues.
Vitamin D Increases calcium absorption in bone,
intestines, kidney. Promotes bone growth and
maintenance.
Stimulates maturation of cells – heart, brain,
immune system, etc.
27.
28. Fat Soluble Vitamin D
Exposure of human skin to sunlight of 295-300 nm
converts 7-dehydrocholesterol to previtamin D.
The isomerization to cholecalciferol (vitamin D3) is
heat catalyzed. Continuous exposure to ultraviolet
radiation from the sun results in the reversible
formation of lumisterol and tachysterol.
Once the B ring of the steroids has been cleaved,
the products should no longer be referred as
steroid.
So Vitamin D is not a steroidal vitamin.
29. Calcium regulation: Role of Vit D
There are at least three hormones that regulate
calcium metabolism, parathyroid (PTH), calcitonin, and
1,25(OH)2D3.
In response to low serum calcium levels, PTH
stimulates the hydroxylation of 25(OH)D3 leading to
formation of calcium transport protein and activation of
osteoclast cells required to release calcium from bone.
PTH also inhibits calcium excretion by the kidney.
In contrast, calcitonin (produced in the thyroid gland)
acts when serum calcium levels are high. It promotes
the deposition of calcium into bone by osteoblast cells
and excretion of calcium by the kidney.
30.
31. Function and deficiency:
One of the most important roles of vitamin D is to maintain
skeletal calcium balance by promoting calcium absorption in the
intestines, promoting bone resorption by increasing osteoclast
number, maintaining calcium and phosphate levels for bone
formation, and allowing proper functioning of parathyroid
hormone to maintain serum calcium levels.
Vitamin D deficiency can result in lower bone mineral density and
an increased risk of reduced bone density (osteoporosis) or bone
fracture because a lack of vitamin D alters mineral metabolism in
the body.
Deficiencies: rickets (children), osteomalacia (adults).
Toxicities (5X RDA)
Loss of calcium from bone and deposition in soft tissues.
Loss of appetite, nausea and vomiting, psychological
depression.
32. Fat Soluble Vitamins
Vitamin D
Daily Requirement – 5 micrograms/day for
ages 19-50, 10 for ages 51-70, 15 for ages
>70.
33. Vitamin: E
Vitamin E includes both tocopherols and tocotrienols.
Tocopherol and Tocotrienols are : *alpha-, beta -,
gamma- and delta-
Most active form is alfa tocopherol.
It is a fat-soluble antioxidant that stops the production
of reactive oxygen species formed when fat undergoes
oxidation.
Roles:
Antioxidant (protects polyunsaturated fats)
Prevention of damage to lungs, RBCs, WBCs
(immunity), heart
Necessary for normal nerve development
34.
35. Vitamin E: Function
As an antioxidant, vitamin E acts as a peroxy
radical scavenger, preventing the propagation of free
radicals in tissues.
By reacting with them to form a tocopheryl radical
which will then be oxidized by a hydrogen donor (such
as Vitamin C) and thus return to its reduced state.
As it is fat-soluble, it is incorporated into cell
membranes, which protects them from oxidative
damage.
Vitamin E also plays a role in neurological functions,
and inhibition of platelet aggregation.
Vitamin E protects lipids and prevents the oxidation of
polyunsaturated fatty acids (PUFAs.)
36. Vitamin E: Function
Vitamin E also has an effect on gene expression.
Scavenger receptor CD36, is a class B scavenger receptor found
to be up-regulated by oxidized low density lipoprotein (LDL) and
binds it.
Treatment with alpha tocopherol was found to down regulate the
expression of the CD36 scavenger receptor gene and the
scavenger receptor class A (SR-A)
37. Vitamin E deficiency and toxicity:
Deficiencies (decreased absorption of fats-
liver disease, low fat diets)
Premature babies – fragile RBCs (hemolysis)
Loss of muscle coordination, vision, impaired
immune functions
Myopathy, retinopathy, ataxia
Toxicities (more than 1000 milligrams/day)
Increases the effects of anticoagulants
(Coumadin, Warfarin)
40. Vitamin K:
It was named Vitamin K for koagulation
vitamin. This may be the only vitamin that
humans receive from bacteria in large
intestine.
Roles:
Promotes synthesis of blood clotting
proteins (**Interferes with Coumadin)
Bone formation
41. Fat Soluble Vitamins
There are two series for this vitamin. The vitamin K1
series (phylloquinone) is mostly obtained from green
plants, whereas the K2 series (menaquinone) is the
product of bacteria.
The active vitamin is in the K2 series.
Menadione has sometimes been referred to as vitamin
K3.
Escherichia coli found in the large intestine, can
synthesize vitamin K2,but not vitamin K1.
42. Vitamin K deficiency:
Three main causes are:
Chronic obstructive jaundice that prevents the release of
bile salts into intestine and decreases absorption of
vitamin K.
Surgery at intestine decreases bacterial flora and that
decreases the production of vitamin K.
Infants born with a sterile intestinal tract may have
hemorrhagic diseases. Until the flora are established, the
infant will have to get vitamin K from the mother.
Toxicities:
>1000 mg/day: rupture of RBCs and jaundice
43.
44. Water Soluble Vitamins
Vitamin B complex:
Tender Romance Never Fails with 6 to
12 Beautiful Pearls
T-Thiamin
R-Riboflavin
N-Niacin,
F-Folate,
B6,
B12,
B-Biotin
P-Pantothenic acid
46. Water Soluble Vitamins
Support and increase the rate of metabolism
Maintain healthy skin, hair and muscle tone
Enhance immune and nervous system function
Promote cell growth and division, including that of the red
blood cells that help to prevent anemia
Reduce the risk of pancreatic cancer
All B vitamins are water-soluble, and are dispersed
throughout the body. Most of the B vitamins must be
replenished regularly, since any excess is excreted in
the urine. This can result in the urine produced being a
bright green-yellow color.
B vitamins have also been hypothesized to reduce the
symptoms of attention deficit hyperactivity disorder.
47. All Vitamin B acts as Cofactors?
A cofactor is a non-protein chemical compound that is bound to
a protein enzymes and is required for the protein's biological
activity. These cofactors can be considered "helper molecules"
that assist in biochemical transformations.
Cofactors are either organic or inorganic. They can also be
classified depending on how tightly they bind to an enzyme, with
loosely-bound cofactors termed coenzymes and tightly-bound
cofactors termed prosthetic groups.
An inactive enzyme, without the cofactor is called an apoenzyme,
while the complete enzyme with cofactor is the holoenzyme.
For example, the multienzyme complex pyruvate dehydrogenase
at the junction of glycolysis and the citric acid cycle requires five
organic cofactors and one metal ion: thiamine
pyrophosphate (TPP), lipoamide and flavin adenine
dinucleotide (FAD), nicotinamide adenine dinucleotide (NAD+
),
coenzyme A (CoA), and a metal ion (Mg2+
).
48. Thiamin: cofactors and roles
Thiamine produces TPP (thiamine pyrophosphate) coenzyme
Thiamine kinase in the intestinal mucosa cell transfers a
pyrophosphate from the ATP to the propyl alcohol at position 5 of
the thiazole ring, forming thiamine pyrophosphate (TPP).
The first role of TPP is the oxidative decarboxylation of a-keto
acids. The two most common examples are pyruvate and a-
ketoglutarate, oxidatively decarboxyated to acetyl CoA and
succinyl CoA, respectively.
TPP is also the coenzyme in the transketolase reaction found
in the pentose phosphate pathway that interconverts hexoses,
pentoses, tetroses, and trioses.
49. Thiamine deficiency:
Beriberi is a nervous system ailment caused by a thiamine
(vitamin B1) deficiency in the diet.
Symptoms include weight loss, emotional disturbances,
impaired sensory perception, weakness and pain in the limbs,
and periods of irregular heart rate, Edema(swelling of bodily
tissues) are common.
It may increase the amount of lactic acid and pyruvic acid within
the blood. In advanced cases, the disease may cause heart
failure and death.
Dry beriberi and Wernicke-Korsakoff syndrome affect the
peripheral and central nervous system respectively.
Wet beriberi affects the cardiovascular system, as well as other
bodily systems.
Infantile beriberi affects mostly children in developing countries.
50. Thiamine deficiency:
Dry beriberi
Dry beriberi causes partial paralysis resulting from damaged
peripheral nerves. It is also referred to as endemic neuritis. It is
characterized by:
Difficulty in walking
Tingling or loss of feeling (sensation) in hands and feet
(numbness)
Loss of muscle function or paralysis of the lower legs
Mental confusion/speech difficulties
Pain
Involuntary eye movements (nystagmus)
Vomiting
51. Thiamine deficiency:
Wet beriberi
It affects the heart; it is sometimes fatal, as it causes a
combination of heart failure and weakening of the capillary walls,
which causes the peripheral tissues to become edematous. It is
also characterized by:
Vasodilation
Peripheral edema
Paroxysmal nocturnal dyspnea
Increased heart rate
Swelling of the lower legs
52. Thiamine deficiency
Alcohol reduces the active transport of the vitamin.
This form of thiamine deficiency is called Wernicke-
Korsakoff syndrome.
53. Riboflavin
Most dietary riboflavin is eaten as the FAD (Flavin adenine
diphosphate) or FMN (Flavin Mononeucleotide) coenzymes
Riboflavin coenzymes are required for most oxidations of carbon-
carbon bonds. Examples include the oxidation of succinyl CoA to
fumarate in the Krebs cycle and introduction of α,β-unsaturation
in β-oxidation of fatty acids.
Riboflavin is also required for the metabolism of other vitamins,
including the reduction of 5,10-methylene tetrahydrofolate to 5-
methyl tetrahydrofolate and interconversion of pyridoxine-
pyridoxal phosphate- pyridoxamine, retinal to retinoic acid,
tryptophan to niacin etc.
Reduction of the oxidized form of glutathione (GSSG) to its
reduced form (GSH) is also FAD dependent
54.
55. Riboflavin deficiency:
Riboflavin deficiency is always accompanied by
deficiency of other vitamins.
In humans, signs and symptoms of riboflavin
deficiency (ariboflavinosis) include cracked and red
lips, inflammation of the lining of mouth and tongue,
mouth ulcers, cracks at the corners of the mouth
(angular cheilitis), and a sore throat.
A deficiency may also cause dry and scaling skin, fluid
in the mucous membranes, and iron-deficiency
anemia.
56. Niacin:
Niacin is also named as nicotinic acid because of
presence of carboxylic acid in 3-position of pyridine.
The corresponding amide that is nicotinamide is the
vitamin that has amide group in that position.
Niacin is a precursor to NAD+/NADH
and NADP+/NADPH, which play
essential metabolic roles in living cells.
Niacin is involved in both DNA repair, and the
production of steroid hormones in the adrenal gland.
57. Niacin:
NAD is the primary coenzyme required for
oxidation/reduction of carbon-oxygen bonds and is
required for oxidative catabolism (glycolysis, β-
oxidation, Krebs cycle)
NADP is the coenzyme in biosynthetic routes (fatty
acid and cholesterol synthesis) and will be part of
oxidation/reduction reactions involving both carbon-
oxygen and carbon-carbon bonds
58. Niacin: deficiency
Niacin deficiency, manifested as pellagra, is
characterized by the four Ds: dermatitis, diarrhea,
depression, and death.
The dermatitis is characterized by a pigmented rash
developing on skin exposed to heat.
Changes in the gastrointestinal tract can lead to
vomiting, constipation, or diarrhea.
Depression is one of the neurological symptoms that
can include apathy, headache, fatigue, and memory
loss.
60. Pantothenic acid:
Its name derives from the Greek pantothen meaning "from
everywhere" and small quantities of pantothenic acid are found in
nearly every food.
Pantothenic acid is used in the synthesis of coenzyme A (CoA).
Coenzyme A may act as an acyl group carrier to form acetyl-CoA and
other related compounds; this is a way to transport carbon atoms
within the cell.
CoA is important in energy metabolism for pyruvate to enter
the tricarboxylic acid cycle (TCA cycle) as acetyl-CoA, and for α-
ketoglutarate to be transformed to succinyl-CoA in the cycle. CoA is
also important in the biosynthesis of many important compounds such
as fatty acids, cholesterol, and acetylcholine.
CoA is also required for acylation and acetylation, which, for example,
are involved in signal transduction and enzyme activation and
deactivation, respectively.
61. Pyridoxine
The vitamin B6 family consists of pyridoxine,
pyridoxal, pyridoxamine, pyridoxine
phosphate, pyridoxal phosphate (PLP), and
pyridoxamine phosphate.
The commercial form is pyridoxine. Pyridoxal
phosphate is the coenzyme form.
Pyridoxal phosphate (PLP) is required for
amino acid metabolism and reactions involving
amino acids.
62. Pyridoxine
The most common of the PLP-catalyzed reactions are
transaminations.
One-half of all transamination reactions involve a-
ketoglutarate as the acceptor of the amine group forming
glutamic acid. Alternatively, glutamic acid donates the
amine group and an a-keto acid is the acceptor forming a
new amino acid.
Another PLP-catalyzed reaction is decarboxylation of amino
acids. These are part of the biosynthesis of
neurotransmitters, including histamine from histidine;
serotonin from tryptophan, dopamine, norepinephrine, and
epinephrine from dihydroxyphenylalanine (dopa) II and y-
aminobutyric acid from glutamic acid, two reactions in
biosynthesis of cysteine from methionine.
63.
64. Biotin:
Biotin consists of two 5-membered rings cis-fused to
each other that can be drawn either as the keto (urea)
or enolic form.
Biotin picks up carbon dioxide that has been activated
by combining with an ATP-donated phosphate,
producing the mixed anhydride of phosphoric and
carbonic acids.
The biotin enolate receives the carbon dioxide,
producing the keto carbon dioxide-releasing
coenzyme.
There are four biotin-dependent carboxylation
reactions, three of which are in the mitochondria.
65. Biotin:
1. Pyruvate carboxylase: This reaction, which converts pyruvate
to oxalaceetate.
2. Acetyl CoA carboxylase: This reaction, found mostly in the
cytosol, is the committed step in the synthesis of fatty acids
3. Propionyl CoA carboxylase: Propionyl CoA is the product from
the catabolism of valine, isoleucine, methionine, and odd-
numbered fatty acids. The carboxylation reaction, found in the
mitochondria, produces methyl malonyl CoA.
4. Β-Methylcrotonyl CoA carboxylase. This mitochondrial
reaction permits the final steps in the catabolism of the
branched-chain amino acid leucine. The final products,
acetoacetate and acetyl CoA, either are oxidative metabolized to
carbon dioxide and water or enter other reactions in lipid
metabolism.
66.
67. Folic acid:
The commercial form of the vitamin is folic acid . It
consists of a pteridine ring attached to a p-
aminobenzoic acid that is attached to the amine of
glutamic acid.
Two biosynthetic changes must occur before it is
active.
First, it must be reduced to tetrahydrofolate by
dihydrofolate reductase in a two-step reduction.
Second, a polyglutamate chain must be attached to
the y-carboxyl of the parent glutamic acid
The most common polyglutamate found in food is 5-
methyltetrahydrofolate polyglutamate
68.
69.
70. Folic acid:
It is obvious that folic acid is a very important vitamin
for biosynthetic reactions, particularly those required
for the biosynthesis of purines, methylation of
deoxyuridylic acid, and regeneration of methionine
from homocysteine.
71. Folic acid deficiency:
The main deficiency is a characteristic megaloblastic
anemia attributed to a shortage of nucleotides required
for the production of erythrocyte precursor cells.
Another clinical sign of folic acid deficiency is neural
tube defects, including spina bifida and anencephaly
(absence of a major portion of the brain, skull, and
scalp).
A third indication of inadequate folic acid is elevated
blood homocysteine levels, with attendant increased
risk of cardiovascular disease.
72.
73. Cobalamin:
Vitamin B-12, also called cobalamin, plays a key role in the
normal functioning of the brain and nervous system, and for the
formation of blood.
It is normally involved in the metabolism of every cell of the
human body, especially affecting DNA synthesis and regulation,
but also fatty acid synthesis and energy production.
A common synthetic form of the vitamin, cyanocobalamin, does
not occur in nature, but is used in many pharmaceuticals and
supplements, and as a food additive, because of its stability and
lower cost.
In the body it is converted to methylcobalamin and
adenosylcobalamin.
Vitamin B12 was discovered from its relationship to the
disease pernicious anemia (red blood cell count is low).
74. Cobalamin:
since B12 is used to regenerate folate in the body. Most vitamin
B12 deficiency symptoms are actually folate deficiency symptoms,
since they include all the effects of pernicious
anemia and megaloblastosis, which are due to poor synthesis of
DNA when the body does not have a proper supply of folic
acid for the production of thymine.
vitamin B12-dependent enzymes are Methylmalonyl Coenzyme A
mutase, and 5-methyltetrahydrofolate-homocysteine
methyltransferase (MTR), also known as methionine synthase.
75. Water Soluble Vitamins
Vitamin C, ascorbic acid
Roles:
Connective tissue development, collagen
Antioxidant
Promotes iron absorption
Protects vitamin E
76. Water Soluble Vitamins
Vitamin C
Deficiency – Scurvy (skin and mucous membrane
damage), anemia.
DRI : 75 – 90 milligrams/day. Increased for
smokers.
Toxicity (> 2grams/day) – pro-oxidant, activates
oxidizing agents.
Notes: can interfere with diagnostic tests for
diabetes, and blood clotting
