1. SIMS 305- Clinical Biochemistry
Dr. Ali Raza
Senior Lecturer
Centre for Human Genetics and Molecular Medicine (CHGMM),
Sindh Institute of Medical Sciences (SIMS), SIUT.
5. Vitamins
• Natural micronutrient organic substances.
• Having specific biochemical functions in the human body
(essential for health maintenance).
Vitamin A helps form and maintain healthy teeth, bones, soft tissue,
mucus membranes, and skin.
Vitamin B12 helps form red blood cells and maintain the central nervous
system.
Vitamin C is an antioxidant that promotes healthy teeth and gums.
helps the body absorb iron and maintain healthy tissue.
promotes wound healing.
6. Vitamins are:
• Required in very tiny (mcgs) and balanced amounts.
• Not made in the body (or not in sufficient quantity)
• Obtained from animals, plants, and microorganisms.
• Their deficiency resulted in a specific diseases.
7. Cases of Vitamin Deficiency and Toxicity
(1). Avitaminosis:
Any disease caused by chronic or long-term vitamin deficiency
or caused by a defect in metabolic conversion, such as
tryptophan to niacin.
It leads to well defined symptoms e.g.
Xerophthalmia due to Vitamin A deficiency.
Rickets due to Vitamin D deficiency.
Pellagra due to Vitamin B3 deficiency.
Beriberi due to Vitamin B1 deficiency.
Scurvy due to Vitamin C deficiency.
8. Cases of Vitamin Deficiency and Toxicity
(2). Hypovitaminosis
• Resulted from inadequate supply of one or more vitamins.
• It appears in the form of well - defined symptoms as
skin changes
reduced vitality and
low resistance to infections.
9. (3). Latent hypovitaminosis:
• A case of unrecognizable deficiency symptoms but
immediately appeared under sudden stress or exposure
to different environment.
• Latent iron deficiency (LID), also called iron-
deficient erythropoiesis,
• medical condition in which there is evidence of iron
deficiency without anemia
10. (4). Hypovitaminosis due to Anti- vitamins:
• Thiaminase in raw fish destroy Vit. B1.
• Avidin in raw egg forming complex with biotin
(vitamin) (biotin – avidin) prevents absorption
of biotin.
• Liatin in linseed oil is antagonist to Vit. B6.
11. 5. Hypervitamninosis:
A case which develops only upon prolonged use
of excessive amount of vitamins.
Hypervitaminosis A
Occurs after large
over dosage of the vitamin.
Symptoms include:
Headache
Abdominal pain
Nausea or vomiting
Lethargy
Visual changes
Impaired consciousness
Hypervitaminosis D
caused by excessive ingestion or
over prescription of prescribed
medications such as calcium with
vit. D.
Symptoms include:
Polyuria
Vomiting
Constipation
Hypertension
Seizures - can be fatal
12. Medicinal applications of Vitamins
Elimination of hypovitaminosis.
Treatment of some diseases.
Prophylaxis against some diseases.
13. Cases of addition of Vitamins to food
1. Vitaminisation:
Addition of vitamins to foods which do not
necessarily contain them naturally
• Addition of vitamins A and D to margarine).
2. Revitaminisation:
Restoration of the original vitamin contents of food that
is lost during processing.
(Flour loss about 70% of its vitamin B content;
Skimmed milk must be revitaminized with
vitamins A and D as they removed on skimming
with fat).
14. Cases of addition of Vitamins to food
3. Standardization:
Compensation of seasonal variations of vitamins in food
(E.g.
• Milk must standardized due to seasonal variation of
vitamin A).
15. 4. Enrichment: Addition of vitamins over the initial
natural level e.g. in Milk and flour.
5. Stabilization of food: Some food products show change
in color and taste due to oxidation by light and air.
Vitamins C and E ( water and fat soluble
antioxidants) are used to protect food from
oxidation and thus saving its nutritional value.
6. Coloring of food products: The carotenoids (natural fat
soluble pigments and pro-vitamin A) and synthetic
carotenoids as: β-carotene, β-apo-8‘- carotenal, and
anthaxanthin are suitable for the coloring of
margarine and cheese.
Editor's Notes
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Latent iron deficiency (LID), also called iron-deficient erythropoiesis,[1]
is a medical condition in which there is evidence of iron deficiency without anemia (normal hemoglobin level).[2]
It is important to assess this condition because it is accepted that individuals with latent iron deficiency will develop iron-deficiency anemia in the weeks or months following diagnoses of LID if they are not treated with iron supplementation.
In addition, there is some evidence of a decrease in vitality and an increase in fatigue among individuals that have LID.[3]