1. 14. Vitamins & Trace Elements

2. What are Trace Elements?
Trace elements are those elements that
occur in human and animal tissues in
mg/kg amounts or less.
Essential when:
deficient intake ►impairment of function
restoration with physiological amounts of only
that element prevents/alleviates impairment.

3. Trace Element Functions
amplification- small amounts produce dramatic effects on
the body e.g. Fe deficiency & anaemia
specificity- cannot be effectively replaced by chemically
similar constituents
homeostasis- regulated mechanisms for absorption,
storage and excretion - storage proteins such as ferritin
& metallothioneins important in regulation of Fe, Zn, Cu
interactions- overabundance of one trace element can
interfere with metabolic use of another e.g. large dietary
Zn affect Cu absorption.

4. Copper e.g. cytochrome oxidase, superoxide dismutase, tyrosinase,
essential trace metal present in many intracellular enzymes
e.g. cytochrome oxidase, superoxide dismutase, tyrosinase,
- present in plasma in association with the copper-binding protein,
ceruloplasmin.
Laboratory Assessment:
1. serum copper : ~10-22 µmol/L, ~ 90% bound to ceruloplasmin
2. serum ceruloplasmin - normal adult levels mg/L
- levels useful in interpretation of serum copper levels.
3. urinary copper : ~ 0.1µmol/day

5. Copper balance

6. Vitamins Definition: Classification:
unrelated organic catalysts that are necessary in trace amounts for normal metabolism
Classification:
Water soluble:
B-Complex: B1 (thiamine), niacin, folate (9), riboflavin (B2), pyridoxine (B6), cyanocobalamin (B12),
Others: ascorbate (C)
Fat-soluble:
A (retinol), D (cholecalciferol), K (phytomenadione), E (tocopherol)

7. Vitamin deficiency Causes: Inadequate intake with normal requirements
Impaired absorption
Impaired metabolism (e.g. vitamin D)
Increased requirements e.g. pregnancy
Increased losses
Functions typically intracellular
Plasma concentrations do not reflect intracellular levels or function – unreliable
Tissue concentrations most reliable but not always easily available

8. Water-soluble Vitamins– folate (B9) & B12 not considered here
sources
function
B1 thiamine
Whole grain cereals, organ meats, flours, nuts, green vegs
Cofactor in metabolism of pyruvate and 2-oxoglutarate and in pentose phosphate shunt (transketolase)
B2 riboflavin
Milk, organ meats, eggs, green vegs
Oxidation-reduction enzymatic actions
B6 pyridoxine
Meat, poultry, fish, potatoes, vegetables
Enzyme systems –amino acid transaminases, phosphorylases, decarboxylases
niacin
Whole grain, meat, fish, legumes, nuts, cereals,
Coenzymes – NAD, NADP – in glycolysis and ox. phosphorylation
C - ascorbate
Citrus fruits, tomatoes, melons, cabbage, straw berries, green vegs
Antioxidant, formation of connective tissue & catecholamines; cholesterol metabolism

9. Fat-soluble Vitamins Vitamin sources function A - retinol
Animal – fish liver oils, butter, milk, liver, eggs Plants – green/yellow vegs, margarine, fruits
Vision, growth of epithelia, immune responses, reproduction, anticancer agent; constituent of retinal pigment rhodopsin
E – tocopherol
Vegetable oils, wheat germ, rice germ, nuts, legumes, green vegs
Antioxidant – membrane stability, cardiovascular disease prevention, RBC function; fertility
K –
Phytomenadione
Green vegetables, spinach, cabbage, liver, synthesis in intestine
Coagulation factors – prothrombin, VII, IX, X; osteocalcins – binding of calcium to proteins
D –
calciferol
Fish liver oils, fortified milk, sun exposure, small amounts in butter, eggs, liver, salmon
Calcification of bone and teeth

10. VITAMIN DEFICIENCIES

12. Complications of Thiamine (vitamin B1) Deficiency (Beri-beri)

13. Complications of Niacin Deficiency (Pellagra)

14. Complications of Riboflavin (vitamin B2) Deficiency

15. Complications of Ascorbate (Vitamin C) Deficiency

16. LESIONS IN SCURVY

17. Classification of Vitamins

18. Hypervitaminosis D: ▲intestinal absorption of Ca, PO4
Hypervitaminosis Classically seen with fat-soluble vitamins: A, D Seen with excessive vitamin nutritional supplements
Hypervitaminosis A
Acute toxicity: neurologic symptoms: headache, vomiting, stupor, papilloedema
Chronic toxicity: neurologic, skeletal (loss of cortical bone), cutaneous (fissuring, ulcers), hepatomegaly with parenchymal damage.
Symptoms subside with discontinuation of excess vit A intake
Hypervitaminosis D: ▲intestinal absorption of Ca, PO4
► hypercalcaemia, hyperphosphataemia, bone resorption
►renal calculi, osteoporosis, metastatic calcification