Vitamin c deficiency disorders

A complete and comprehensive lecture on vitamin c deficiency disorder

1. Vitamin C Deficiency Disorders Nutritional Deficiency Disorders Roshina Rabail Lecturer, government college women university, Faisalabad, Pakistan M.Phil Human Nutrition and Dietetics Former Dietitian CMH Okara Cantt . & Shifa Int. Hospital Islamabad Roshina Rabail 1

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3. Vitamin C Vitamin C (L- ascorbic acid ) structurally resembles a monosaccharide sugar (Glucose). Essential micronutrient; Water soluble vitamin, that acts as an antioxidant, electron donor. Very less stable to heat and light; 70 percentage lost in the process of cooking. Most animals & plants can synthesize ascorbic acid from glucose. Roshina Rabail 3

4. Sources Foods high in vitamin C include the following. Citrus fruits, especially grapefruits and lemons, limes , oranges , peaches, strawberries, bananas. Vegetables , including broccoli, green peppers, tomatoes, potatoes, and cabbage.

5. Functions of Vitamin C Oxidation of tyrosine and phenylalanine Formation of hydroxyproline , P reventing depolymerization of collagen Important in hemopoiesis Synthesis of collagen , carnitine, hormone and amino acids E ssential for wound healing F acilitates recovery from burns Supports immune function Facilitates the absorption of iron . Roshina Rabail 5

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7. Functions of Vitamin C Collagen synthesis: Ascorbic acid is necessary for the post transilational hydroxylation of proline & lysine Residues. Hydroxy proline & hydroxy lysine form cross links in collagen- gives tensile strength to fibers. This process is necessary for the normal production of supporting tissues like osteoid, collagen, and intercellular cement substances of capillaries Roshina Rabail 7

8. Functions of Vitamin C Iron metabolism: Vit C reduces Ferric to Ferrous to help absorbed from intestine. Hemoglobin metabolism: Reconversion of met-hemoglobin to hemoglobin. Folic acid metabolism: Helps the enzyme folate reductase to reduce folic acid to tetrahydrofolic acid. Thus helps in maturation of RBC. Roshina Rabail 8

9. Functions of Vitamin C Tyrosine metabolism: Oxydation of parahydroxyphenylpyruvate to homogenitisic acid. Tryptophan metabolism: Hydroxylation of tryptophan to 5-hydroxyl tryptophan- formation of serotonin. Roshina Rabail 9

10. Steroid synthesis: Has some role in adrenal steroidogenesis. Vit C is present in adrenal cortex- depleted by ACTH stimulation. Strengthen Immune system : Stimulates phagocytic action of WBC. Eye Health: Vit C is concentrated in the lens of eye. Regular intake of vit C reduces risk of cataract formation. Antioxidant property: Ability to scavenge free radicals directly. Participate in metaboluc reactions that regenerate antioxidant form of vit E. Roshina Rabail 10 Functions of Vit . C

11. RDA Roshina Rabail 11

12. Dietary factors determining vitamin C status Factor Summary and Comments Dietary intake Dietary intake, particularly fruit intake, correlates with improved vitamin C status and decreased prevalence of deficiency; is dependent on the amount consumed, frequency of consumption, and type of food consumed as the vitamin C content of food varies. High dietary fat and sugar intake are associated with decreased vitamin C intake and status. Staple foods Staple foods such as grains (e.g., rice, millet, wheat/couscous, corn) and some starchy roots and tubers are low in vitamin C; populations who consume these staples can have lower overall vitamin C intake. Traditional cooking practices Through boiling or steaming, water-soluble vitamins may be leached from food and prolonged cooking of food can destroy vitamin C; this could lead to decreased vitamin C status in certain social or ethnic groups. Drying of leafy vegetables also decreases water-soluble vitamins. Supplement use Supplement users have significantly higher vitamin C status and negligible prevalence of deficiency. Non-users have a 2–3 fold odds ratio of insucient and deficient vitamin C status. Roshina Rabail 12

13. Vitamin C Deficiency Called Scurvy and its symptoms generally develop after 3 months of severe or total vit C deficiency. Gross deficiency of vitamin C is characterized by: bone diseases in growing children hemorrhages healing defects in both children & adults . Roshina Rabail 13

14. Vitamin C Deficiency Formation of intercellular cement substances in connective tissues, bones, and dentin is defective, resulting in weakened capillaries with subsequent hemorrhage and defects in bone and related structures. Hemorrhaging is a hallmark feature of scurvy and can occur in any organ. Hair follicles are one of the common sites of cutaneous bleeding. Bone tissue formation becomes impaired, which, in children, causes bone lesions and poor bone growth . Roshina Rabail 14

15. Who are at Risk? Babies who are fed only cow's milk during the first year of life are at risk. Alcoholism Elderly/ Retired people who live alone Those who eat primarily fast food Cigarette smokers require increased intake of vitamin C because of lower vitamin C absorption and increased catabolism . Pregnant and lactating women and those with thyrotoxicosis require increased intake of vitamin C because of increased utilization . Economically disadvantaged persons tend to not purchase foods high in vitamin C. Roshina Rabail 15

16. Refugees who are dependent on external suppliers for their food and have limited access to fresh fruits and vegetables. People with anorexia nervosa or anorexia from other diseases such as AIDS or cancer are at increased risk of vitamin C deficiency. People with type 1 diabetes have increased vitamin C requirements, as do those on hemodialysis and peritoneal dialysis. Because vitamin C is absorbed in the small intestine, people with disease of the small intestine such as Crohn’s, Whipple, and celiac disease are at risk. Iron overload disorders may lead to renal vitamin C wasting. Roshina Rabail 16 Who are at Risk?

17. Symptoms of Vitamin C Deficiency Early symptoms: discomfort, fatigue and lethargy. After 1-3 months: patients develop shortness of breath and bone pain. Long Term Outcomes: Myalgias (muscular aches) due to reduced carnitine. Bruising easily & bleeding from weakened blood vessels, connective tissue & bones due to collagen loss. Dry mouth, dry eyes, Hair & teeth loss Gingivitis : gums become painful, swollen & spongy, friability, bleeding, and infection with loose teeth Roshina Rabail 17

18. Skin : roughness, easy bruising and petechiae , Perifollicular hemorrhages ( See figure), purpura , and ecchymoses are seen most commonly on the legs and buttocks where hydrostatic pressure is the greatest . Poor wound healing and breakdown of old scars may be seen. Hair: Alopecia may occur secondary to reduced disulfide bonding. Nails: Splinter hemorrhages may occur . Roshina Rabail 18 Symptoms of Vitamin C Deficiency

19. Eye: Scleral icterus (late, probably secondary to hemolysis ); and pale conjunctiva are seen. Conjunctival hemorrhage: Bleeding into the periorbital area, eyelids, and retrobulbar space also can be seen. Chest and cardiovascular: Scorbutic rosary ( ie , sternum sinks inward/beaded appearance of anterior ends of ribs) may occur in children . High-output heart failure due to anemia can be observed. Bleeding into the myocardium and pericardial space has been reported. Roshina Rabail 19 Symptoms of Vitamin C Deficiency

20. Extremities: Fractures , dislocations, and tenderness of bones are common in children. Bleeding into muscles and joints may be seen. Edema may occur late in the disease. Gastrointestinal : Loss of weight secondary to anorexia is common . In the late stages , jaundice, generalized edema, oliguria, neuropathy, fever, and convulsions can be seen. Vital signs: Hypotension may be observed late in the disease. This may be due to an inability of the resistance vessels to constrict in response to adrenergic stimuli. Roshina Rabail 20 Symptoms of Vitamin C Deficiency

21. Infantile scurvy (Barlow's disease ) Infantile scurvy is characterized by gross irritability, excessive crying and tenderness to touch, more so in the lower limbs. Scurvy occurs usually in infants between the age of 6 months to 2 years. No age is a bar, however . The infant adopts the so-called " frogposition ”. The posture of the lower limbs gives an impression as though these are paralyzed. Infants have pain when they move & lose their appetite. Infants do not gain weight as they normally do. In infants & children bone growth is impaired & bleeding & anemia may occur. In infants between 6 to 12 months of age diet should be supplemented with vitamin C sources. Roshina Rabail 21

22. In bones, deficiency results in failure of osteoblast to form the intercellular ground substance osteoid The resulting scorbutic bone is weak & fractures easily Hemorrhage into joint cavity lead to painful swelling of the joint Microcytic hypochromic anemia is seen with Poikilocytosis ( red blood cells of varying sizes ) & anisocytosis ( red blood cells of varying shapes). Reason for anemia may be: loss of blood by hemorrhage decreased iron absorption decreased tetra hydro folic acid THFA Roshina Rabail 22 Infantile scurvy (Barlow's disease )

23. Diagnosis A plasma or leukocyte vitamin C level can confirm clinical diagnosis. Scurvy occurs at levels generally less than 0.1 mg/ dL . Symptoms occur at levels below 2.5 mg/L, which is considered deficiency. Levels of 2.5-5 mg/L indicate depletion. Levels can be low in patients who have tuberculosis , rheumatic fever, or other chronic illnesses; those who smoke cigarettes; and patients on oral contraceptive drugs. Capillary fragility can be checked by inflating a blood pressure cuff and looking for petechiae on the forearm. Bleeding time, clotting time and Prothrombin are estimated to rule out other bleeding disorders Roshina Rabail 23

24. Treatment/management It consists in giving a dose of 500 mg of vitamin C followed by a daily dose of 100 to 300 mg for several weeks. Oral administration is good enough. Or patients should take ascorbic acid at 100 mg 3-5 times a day until total of 4 g is reached , and then they should decrease intake to 100 mg daily . Divided doses are better to be given because intestinal absorption is limited to 100 mg at one time. Parenteral doses are necessary in those with gastrointestinal malabsorption . Roshina Rabail 24

25. References Vitamin C Deficiency by Namrata ; Biochemistry for medics. Carr A. C. and Rowe S. (2020) Factors Aecting Vitamin C Status and Prevalence of Deficiency : A Global Health Perspective. Nutrients 2020, 12, 1963; doi:10.3390/nu12071963 Roshina Rabail 25