NOTA SLAID

• Excessive Ca in the arteries contributes to a
build-up of Ca deposits on the artery walls
making them thick

• Vitamin K pumps Ca out of arteries and
redirects it to the bones where it is mostly
needed to prevent osteoporosis

Lowers risk of Alzheimer’s

• Individuals with Alzheimer’s have an abnormal
Ca metabolism in the brain

• Vitamin K helps regulate and restricts Ca
deposits

Deficiency

• Deficiency is rare
• Deficiency usually related with:

– lipid malabsorption
– destruction of intestinal flora

• Susceptible groups

– Newborn baby
– Liver damage or disease (e.g. alcoholics), cystic

fibrosis, inflammatory bowel diseases

– Bulimics, on stringent diets, taking anticoagulants

• Symptoms of deficiency include:

– anemia, bruising, and bleeding of the gums or
nose, and heavy menstrual bleeding

Hemorrhagic disease of newborn:

• Newborn are susceptible to prothrombin

(essential component of the blood-clotting mechanism)

deficiency during 1st few days of life

– due to poor placental transfer of vitamin K

• Failure to establish vitamin K-producing
intestinal flora

• Breast milk < vitamin K than cow’s milk &
because its sterile, its consumption delays
development of intestinal flora

Toxicity

• No known toxicity vitamin K1 or K2

– so no tolerable upper intake level has been set

• Vitamin K3 (the synthetic form) is
demonstrably toxic

– large doses have been shown to cause allergic
reactions, hemolytic anemia, and cytotoxicity in
liver cells

7.3
Water soluble
vitamins: B,C

9 Water-soluble vitamins = 8B’s and 1C!

B1 = Thiamin
B2 = Riboflavin
B3 = Niacin
B5 = Pantothenic Acid
B6 = Pyridoxine
B7 = Biotin
B9 = Folate
B12 = Cobalamin
Vitamin C

Easily destroyed by heat, light, and oxidation

Primary FUNCTIONS
function
• Act as coenzymes: B vitamins
Other function • Energy metabolism: B vitamins

• Antioxidant: Vitamin C
• Nerve function: Thiamin (B1)
• Protein synthesis: Niacin (B3)
• Formation of red blood cells: Folate (B9) and

Cobalamin (B12)
• Heart health promoted by several B vitamins

Primary function - act as coenzymes

• B vitamins act as coenzymes

• Coenzymes are a vital part of some enzymes

• so vitamins are needed for enzyme to work properly

+ Active enzyme

Inactive enzyme Coenzyme (vitamin)

• Coenzymes are small and organic molecules that
interact with enzymes to enable enzymes to
function

• Coenzyme combine with inactive enzyme to form
active enzyme that are able to catalyze specific
reactions

• The coenzyme contribute to enzyme activity

B vitamins and Coenzyme examples

B Vitamin Coenzyme example Abbreviation
Thiamin Thiamine pyrophosphate TPP
Riboflavin Flavin adenine dinucleotide FAD
Flavin mononucleotide FMN
Niacin Nicotinamide adenine dinucleotide NAD
Nicotinamide adenine dinucleotide phosphate NADP

Pantothenic acid Coenzyme A CoA
Biotin N-carboxylbiotinyl lysine
PLP
Vitamin B6 Pyridoxal phosphate THFA
Folic acid Tetrahydrofolic acid
Vitamin B12 Methylscobalamine

Thiamine (B1)

• The first B vitamin identified
• Easily destroyed by heat or oxidation
• Destroyed in basic (alkaline) solutions

• Chemical properties

• the name “thiamin” indicates it contains both sulfur (thio) and
nitrogen (amine)

• consists of a central carbon attached to a 6-member nitrogen-
containing ring and a 5-member sulfur-containing ring

Functions

• Play role in energy metabolism

• Thiamin functions as the co-enzyme thiamin pyrophosphate (TPP)
• in the metabolism of carbohydrates and branched-chain amino acids.

Thiamin and Thiamin Pyrophosphate (TPP)

TPP in Energy Metabolism

• Thiamin is also essential for

• normal growth and development and
• helps to maintain proper functioning of the heart and the nervous and

digestive systems.

• Thiamin cannot be stored in the body;

• however, once absorbed, the vitamin is concentrated in muscle tissue.

RNI for Malaysia (2017)

Age group 0 – 5 months mg/day
Infant 6 – 11 months 0.2
0.3
Children 1 – 3 years 0.5
4 – 6 years 0.6
≥10 years (Male) 7 – 9 years 0.9
≥10 years (Female) 1.2
1.1
Pregnancy 1.4
Lactation 1.5

Food Sources

• Found throughout the food supply, although most food contains
small amounts

• Major sources of thiamine include pork products, whole and enriched
grain and cereal, green beans, milk, asparagus, meats, peanuts, dried
beans, mushrooms and seeds.

Toxicity

• No known toxicity
• No Tolerable Upper Intake Level established

Deficiency

• Beriberi

• Extreme weakness – impairs the nervous, muscle, gastrointestinal and
cardiovascular systems.

• Wasting (weight loss), impaired sensory perception, confusion, muscle
weakness, peripheral neuropathy - nerve degeneration, arythmia

• The nervous system is especially affected
because of its reliance on glucose for energy

• In thiamine deficiency, glucose metabolism is
severely disrupted

Classifications:

Dry (without edema) Wet Infantile

• The main symptoms are • In addition of • From infancy thiamine
related to the nervous neurological symptoms, deficiency
and muscular systems. cardiovascular system is
affected.
• Peripheral nerve
damage, wasting • Edema and congestive
without edema. heart failure
Psychological disorders



• Wernicke-Korsakoff Syndrome

• Also known as cerebral beriberi
• Found mainly among heavy users of alcohol
• The symptoms include changes in vision (double vision, crossed eyes, rapid

eye movements), ataxia (loss of full control of bodily movements), and
impaired mental functions

3 prolonged problem related to thiamine:

Alcohol decreases
Alcohol thiamin
Alcoholic absorption

increases
thiamin
excretion in the

urine

may consume a
poor-quality
diet without

enough vitamin

Riboflavin (B2)

• Relatively stable, resistant to acid, heat and oxidation
• However, is unstable in alkali and light
• Slightly soluble in water
• Called “yellow enzyme”

Functions

• The main function is to help the body to convert carbohydrate to
energy.

• Riboflavin is important for the metabolism of carbohydrate, amino
acids and lipids.

• It carries out these functions as coenzymes:

• flavin adenine dinucleotide (FAD) and
• flavin adenine mononucleotide (FMN)

156

Structures of Riboflavin,
FAD and FMN

• As they can accept and transfer H+, they mostly function in oxidation-
reduction reactions

• Riboflavin facilitates energy metabolism in the body

158

Source: Henriques et al. (2010)

• The two coenzymes play major roles in energy production, cellular
function, growth and development and metabolism of fat.

• Due to its fundamental roles in metabolism,

• riboflavin deficiencies are first evident in tissues such as skin and epithelia.

• Riboflavin also acts as an antioxidant

• due to its ability to activate antioxidant enzymes.
• Antioxidants fight free radicals and reduce DNA damage.

• Riboflavin also has a role in helping the body to convert vitamin B6 to
folate to a form that it can be used in the body.

RNI for Malaysia (2017)

Age group 0 – 5 months mg/day
Infant 6 – 11 months 0.3
0.4
Children 1 – 3 years 0.5
4 – 6 years 0.6
≥10 years (Male) 7 – 9 years 0.9
Adolescent (Female) 1.3
≥19 years (Female) 10 – 18 years 1.0
1.1
Pregnancy 1.4
Lactation 1.6

• No known problems associated with high intakes of riboflavin, so no
Upper Level has been set

163

Food Sources

• Milk and milk products are good source of riboflavin
• Other food rich in riboflavin – enriched breads, cereals and other

grain products, meat (liver and heart), mushrooms, green leafy
vegetables, cottage cheese

164

• Riboflavin is also synthesized by bacteria in GI tract
• Exposure to light (UV light) causes riboflavin to

break down rapidly

• Riboflavin is stable to heat, so cooking does not
destroy it

Toxicity

• No reported toxicity
• The current levels of intake of riboflavin from all sources do not

represent a risk to human health

Deficiency

• Ariboflavinosis
• Cracks at the corner of the mouth (angular stomatitis)
• Lips become inflamed and split (cheilosis)
• Dermatitis around the nose
• Inflammation of the tongue (glossitis)
• Moist, red, scaly skin (seborrheic dermatitis)

167



• Biochemical evidence of deficiency

• low riboflavin levels in red blood cells or reduced activity of the enzyme
glutathione reductase

• Diseases such as cancer, certain forms of cardiovascular disease, and
diabetes can lead to or worsen a riboflavin deficiency

169

• People with alcoholism, malabsorption disorders, elderly, or very poor
diets at risk of riboflavin deficiency

170

Niacin (B3)

• 2 Active forms from food: Nicotinic Acid and Nicotinamide
• Converted to Coenzymes

• Nicotinamide adenine dinucleotide (NAD)
• Nicotinamide adenine dinucleotide phosphate (NADP)

Niacin and Coenzymes NAD and NADP