กิตติกรรมประกาศ

กิตติกรรมประกาศ

ผลลัพธ์ (อังกฤษ) 1:

Acknowledgements

ผลลัพธ์ (อังกฤษ) 2:

acknowledgment

ผลลัพธ์ (อังกฤษ) 3:

VITAMIN C DEFICIENCY.In developed countries vitamin C, deficiency can occur as part of, general undernutrition but severe deficiency (causing. Scurvy) is uncommon. Symptoms, include fatigue depression and connective, tissue defects (eg gingivitis petechiae rash,,,,, Internal bleeding impaired wound, healing). In infants, and children bone growth may be impaired. Diagnosis is usually, clinical. Treatment consists of oral vitamin C.Severe deficiency results in scurvy a disorder, characterized by hemorrhagic manifestations and abnormal osteoid and dentin. Formation.Etiology.In adults primary deficiency, is usually due to.Inadequate diet.The need for dietary vitamin C is increased by, febrile illnesses inflammatory disorders (particularly diarrheal disorders),. Achlorhydria smoking hyperthyroidism,,,, iron deficiency cold or heat stress surgery burns and,,, protein deficiency. Heat. (eg sterilization of, formulas cooking), can destroy some of the vitamin C in food.Pathophysiology.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.Bone tissue formation becomes impaired which in children,,, bone causes lesions and poor bone growth. Fibrous tissue forms. Between the diaphysis and, the epiphysis and costochondral junctions enlarge. Densely calcified fragments of cartilage are. Embedded in the fibrous tissue. Subperiosteal hemorrhages sometimes due, to small fractures may occur, in children or adults.Symptoms and Signs.In adults symptoms develop, after weeks to months of vitamin C depletion. Lassitude weakness irritability weight loss,,,,, And vague myalgias and arthralgias may develop early.Later symptoms related, to defects in connective tissues develop. Follicular hyperkeratosis coiled hair and perifollicular,,, Hemorrhages may develop. Gums may become swollen purple spongy and,,, friable; they bleed easily in severe deficiency, Eventually,. Teeth become loose and avulsed. Secondary infections may develop. Wounds heal poorly and tear easily and spontaneous, hemorrhages. May occur especially as, ecchymoses in the skin of the lower limbs or as bulbar conjunctival hemorrhage.Other symptoms and signs include femoral neuropathy due to hemorrhage into femoral sheaths (which may mimic deep venous. Thrombosis), lower extremity edema and painful, bleeding or effusions within joints.Diagnosis.Usually clinical (based on skin or gingival findings and risk factors).Diagnosis is usually made clinically in a patient who has skin or gingival signs and is at risk of vitamin C, deficiency. Laboratory confirmation may be available. CBC is done often detecting, anemia. Bleeding coagulation and prothrombin times,,, Are normal.Skeletal X-rays can help diagnose childhood (but not adult) scurvy. Changes are most evident at the ends of, long bones. Particularly at the knee. Early changes resemble atrophy. Loss of trabeculae results in a ground-glass appearance. The cortex. Thins. A line, of calcified irregular cartilage (white line of Fraenkel) may be visible at the metaphysis. A zone of rarefaction. Or a linear fracture proximal and parallel to the white line may be visible as only a triangular defect at the bone s lateral. ' Margin but is specific. The epiphysis may be compressed. Healing subperiosteal hemorrhages may elevate and calcify the periosteum.Laboratory diagnosis which requires, measuring blood ascorbic acid is sometimes, done at academic centers. Levels of < 0.6 mg / dL. (< 34 could mol / L) are considered marginal; levels of < 0.2 mg / dL (< 11 could mol / L) indicate vitamin C deficiency. Measurement of. Ascorbic acid levels in the WBC-platelet layer of centrifuged blood is not widely available or standardized.In adults scurvy must, be differentiated from arthritis hemorrhagic disorders,,, gingivitis and protein-energy undernutrition.? Hyperkeratotic hair follicles with surrounding hyperemia or hemorrhage are almost pathognomonic. Bleeding gums conjunctival,, ,, hemorrhages most petechiae and ecchymoses are nonspecific.Treatment.Nutritious diet with supplemental ascorbic acid.For scurvy, in adults ascorbic acid 100 to 500 mg PO TID is given for 1 to 2 wk until disappear and, signs, followed by. A nutritious diet supplying 1 to 2 times the daily recommended intake.In scurvy therapeutic doses, of ascorbic acid restore the functions of vitamin C in a few days. The symptoms and signs. Usually disappear over 1 to 2 wk. Chronic gingivitis with extensive subcutaneous hemorrhage persists longer.Prevention.Vitamin C 75 mg PO once / day for women and 90 mg PO once / day for men prevents deficiency. Smokers should consume an additional 35 mg / day.? Five servings of most fruits and vegetables (recommended daily) provide > 200 mg of vitamin C.Key Points.The need for vitamin C is increased by fever inflammation diarrhea smoking,,,,,, hyperthyroidism iron deficiency cold or. Heat stress surgery,,