Vitamin C (Ascorbic acid)

What sample is needed for Vitamin C?

1. Serum or plasma can be used.
2. The whole blood for vitamin C is stable for 3 hours when refrigerated.
3. Deproteinized the serum or plasma with metaphosphoric acid (5 g/dL) or trichloroacetic acid (10 g/dL).

What are the precautions for Vitamin C?

1. Avoid hemolysis.
2. Avoid exposure to light.
3. Use the fresh sample, as it will deteriorate if kept longer.
4. Keep at a low temperature or on ice to avoid oxidation.
5. Avoid exposure to air as it will oxidize to dehydroascorbic acid.

What are the indications for Vitamin C estimation?

1. It helps to diagnose scurvy.
2. In case of delayed wound healing.
3. In the case of renal stone formation.
4. To assess the chronic diseases.

How will you define vitamin C?

Vitamin C, or ascorbic acid, is a water-soluble vitamin essential for various bodily functions:

1. Immune support.
2. Collagen synthesis.
3. Antioxidant activity.
4. Since the human body cannot synthesize it, vitamin C must be obtained from dietary sources or supplements.

How would you discuss the pathophysiology of Vitamin C (Ascorbic acid)?

1. Plants and some animals can synthesize Vitamin C, but humans cannot. Therefore, dietary intake is important for humans.
2. This white crystalline solid is easily soluble in water and easily absorbed from the stomach and intestine.
3. These are strong reducing compounds, and the source is dietary ingestion.
4. Body stores can last for months.
5. Vitamin C is a reducing agent in several hydroxylation reactions in the body.
6. This exists in two forms:
   1. L-ascorbic acid.
   2. Dehydroascorbic acid (Ascarbone).
      1. This form is more labile and biologically active.
7. Absorption is mainly from the stomach and small intestine.
   1. This has passive entry into the WBCs and RBCs.
   2. Active entry is into glandular tissue like the pituitary gland, adrenal cortex, corpus luteum, and thymus.
   3. At the same time, concentration in the retina is 20 to 30 times more than in tissue.
8. Vitamin C is excreted in the urine. Its excretion is increased by:
   1. Aspirin.
   2. Aminopyrine.
   3. Barbiturates.
   4. Paraldehyde.
   5. Hydantoin.

What are the functions of Vitamin C?

1. Vitamin C has a very important function in our body.
2. It is a water-soluble vitamin.
3. This is essential for converting proline and lysine in procollagen to hydroxyproline and hydroxylysine.
   1. Vitamin C is essential in the formation and stabilization of the collagen.
4. Vitamin C may be involved in the stimulation of the synthesis of collagen.
5. It is a powerful antioxidant that protects from oxidative stress and free radical damage.
6. It boosts the immunity.
7. It helps in wound healing.
8. Plays a role in neurotransmitter synthesis and cognitive function.
9. It helps in the absorption of the iron.

What are the sources of vitamin C?

1. The best sources of Vitamin C are:
   1. Citrus fruits. This is the major source.
   2. Berries.
   3. Melons.
   4. Green pepper.
   5. Tomatoes.
   6. Raw cabbage.
   7. Leafy green vegetables.
   8. Potatoes.
2. Heat can lead to the loss of vitamin C.

Vitamin C absorption

What will the presentation of Vitamin C deficiency be?

How will you discuss the Scurvy?

History of scurvy:

1. In 1747, a naval surgeon found that citrus fruits help scurvy patients.
2. This anti-scurvy agent was isolated in 1932 and was vitamin C.
3. It was given the name ascorbic acid because of its antiscorbutic effect.

What are the Clinical effects of scurvy?

1. Several months are needed before the scurvy develops.
2. Vitamin C deficiency leads to Scurvy, which will show clinically:
   1. Hemorrhagic disorder. There may be bruising and ecchymosis.
   2. Impaired college synthesis leads to petechiae and bruising.
   3. There are swollen and bleeding gums.
   4. There is a loss of teeth.
   5. There is impaired healing.
   6. There is anemia.
   7. There is weakness in the lower extremities.

How will you summarize the scurvy?

1. Early weakness, lassitude, and irritability.
2. Vague aches and pain.
3. In the late stage, hemorrhage into the skin, GI tract, and urinary tract.
4. There are osteoporotic changes in the bone.
5. Defective tooth formation.
6. There is anemia.
7. There is delayed wound healing.
8. There may be a fever.

What is the normal Vitamin C (Ascorbic acid)?

Source 1

• Vitamin C = 0.4 to 1.5 mg/dL
• Deficiency level = <0.2 mg/dL

Other sources

1. Daily requirements of vitamin C:
2.  Infants
   1. 0 to 6 months =  40 mg/day
   2. 7 to 12 months = 50 mg/day
3. Children
   1. 1 to  3 years =  15 mg/day
   2. 4 to 8 years = 25 mg/day
   3. 9 to 13 years =  45 mg/day
4. Adolescents
   1. Girls 14 to 18 years = 65 mg/day
   2. Pregnant teens =  80 mg/day
   3. Breastfeeding teens =  115 mg/day
   4. Boys 14 to 18 years = 75 mg/day
5. Adults
   1. Men age 19 and older =  90 mg/day
   2. Women age 19 years and older: = 75 mg/day
   3. Pregnant women =  85 mg/day
   4. Breastfeeding women = 120 mg/day
6. Vitamin C normal range = 0.2 to 2.0 mg / 100 ml.
7. Deficiency when a level is < 0.2 mg/dL.
8. Vitamin C level in Leucocytes = 20 to 53 µg/10⁸ leucocytes.
   1. Deficient value when it is  <10 µg / 10⁸ leucocytes.
9. Urinary excretion of vitamin C = 8 to 27 mg/day.

What is the clinical presentation of the deficiency of Vitamin C?

1. Prolonged deficiency leads to Scurvy.
2. There is an inadequate formation of intercellular substances in the connective tissue leads to the following:
   1. Swollen, tender, and sometimes bleeding into the joints.
   2. Gums are swollen.
3. Infantile scurvy, also knew Barlow’s disease, will show bayonet rib syndrome.
4. There is vascular fragility leads to:
   1. Cutaneous bleeding usually starts in the lower thigh and may spread to the buttocks, abdomen, arms, and legs.
   2. Petechial hemorrhage may lead to a large bruise.
   3. There is an ocular hemorrhage.
   4. Bleeding in the GI tract, kidneys, conjunctiva, and brain.
   5. Hemorrhage of the gingiva.
5. There may be dental loss and even fractures.
6. There is delayed wound healing.
7. Other glands like salivary, lacrimal, and parotid may be involved.
8. There may be femoral neuropathy and edema of the lower extremities.

What is the presentation of the toxicity of Vitamin C?

1. Large doses of vitamin C for allergies and colds are not recommended.
2. Large doses do not cause any problems except GI upset.
3. Increased oxalate stones in the kidney and urinary bladder due to urine acidification.

What is the presentation of the clinical effects of increased Vitamin C?

1. When vitamin C is more than>2000 mg/day, it may cause:
   1. Diarrhea.
   2. Nausea and dyspepsia.
   3. Over absorption of iron.
   4. A stone formation is like oxalate stones due to the increased secretion of oxalate.
   5. There may be increased secretion of urates.
   6. Effect on diabetes tests and occult blood.

How can you measure Vitamin C?

1. This can be measured by:
   1. Photometric system
   2. Fluorometric and HPLC techniques can be used.

How will you treat for Vitamin C deficiency?

•  The daily dose of  10 mg of vitamin C is sufficient to treat the clinical signs of scurvy.

Questions and answers: