Vitamin C

Vitamin C, also known as ascorbic acid, is an important water-soluble vitamin that is associated with many metabolisms in the body. The human body cannot be synthesized and stored, and must be ingested from the outside. It is rich in fresh green leafy vegetables, oranges, pomelo and lemons. In the case of normal doses, the vitamin C in vivo inventory is 1500 mg. Insufficient intake of vitamin C, malabsorption or increased demand can cause illness. Infants often suffer from a deficiency in vitamin C in the mother's milk, which causes insufficient vitamin C content in the milk. Basic Information Specialist classification: growth and development check classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: The main manifestations of vitamin C deficiency are hemorrhage, bone changes (such as subperiosteal hemorrhage, fracture, dry dislocation) gingivitis and poor wound healing. Normal value: White blood cell-platelet layer vitamin C: 1.425-1.710 mmol Above normal: Can cause diarrhea, rash, increased gastric acid, reflux of gastric juice, fashion can be seen in urinary calculi, increased urinary oxalate and urate excretion, deep vein thrombosis, intravascular hemolysis or coagulation, sometimes leading to leukocyte phagocytic ability reduce. negative: Positive: Tips: cooperate with the doctor to do the appropriate check. Normal value Determination of serum (plasma) vitamin C content should be taken after fasting for vitamin C content determination. Blood white blood cell-platelet layer vitamin C content determination of vitamin C content per 100 grams of white blood cells <1.425mmol is insufficient, between 1.425 ~ 1.710mmol is normal, between 1.710 ~ 1.995mmol is sufficient, > 1.995mmol is saturated. Determination of urinary vitamin C content 24h urine vitamin C content is 20 ~ 40mg. Another load test, 4h urine was collected after oral administration of vitamin C500mg, and the amount of vitamin C excreted in urine was measured. Vitamin C<5mg was insufficient, 5-13mg was normal, and >13mg was sufficient (2,4-dinitrobenzopyrene ratio) Color method). Vitamin C < 3 mg is insufficient, 3 to 10 mg is normal, and > 10 mg is sufficient (2,6-dichloropurine method). Clinical significance Abnormal result Clinical diagnosis of vitamin C deficiency (vitaminCdeficiency) is also known as scurvey. The main manifestations of vitamin C deficiency are hemorrhage, bone changes (such as subperiosteal hemorrhage, fracture, dry dislocation) gingivitis and poor wound healing. The diagnosis of vitamin C deficiency is based on medical history, typical clinical manifestations, and changes in long bones on X-ray films. Determination of vitamin C, leukocyte-platelet layer or urinary vitamin C value is performed when necessary. Low results may be diseases: vitamin C deficiency in children, vitamin C deficiency, osteogenesis imperfecta, polio, pediatric sugar malabsorption, polio, glucose-6-phosphate dehydrogenase deficiency, urinary tract infection High possible disease: neonatal cyanosis Requirements for inspection: cooperate with the doctor to do the appropriate inspection. Inspection process Check operation: 1. Pipette 2.5 ml of the metaphosphoric acid solution and 0.5 ml of serum, mix well, and centrifuge for about 10 minutes. Pipette 1.2 ml of the supernatant and add it to a 13×100 mm screw plug test tube. Make two parallel tubes for each specimen. 2. Take 1.2ml of each standard application standard solution and add it to each other 13×100mm screw plug test tube. Make two parallel tubes for each standard. 4. In each of the above tubes, 0.4 ml of DTC reagent was added, covered, mixed, and incubated in a 37 ° C water bath for 3 h. 5. Allow each tube to cool in an ice bath for 10 min, then slowly add 2.0 ml of pre-cooled 12 mol/L sulfuric acid to each tube, carefully mix and immediately put back into the ice bath. 6. Adjust the spectrophotometer to absorbance zero at 520 nm with a metaphosphoric acid blank tube, then read the absorbance of the standard and unknown samples. Evaluation of laboratory diagnostic methods: 1 Determination of plasma vitamin C content: It only reflects the intake of vitamin C in the diet, can not reflect the storage of vitamin C in the body, so the lower results can not confirm the existence of scurvy. Regardless of the type of diet, women's plasma levels of vitamin C are 20% higher than men's. 2 blood leukocyte-platelet layer vitamin C content; its value can reflect the storage of vitamin C in the tissue, not affected by the recent intake of vitamin C in the diet. If the vitamin C content is zero, indicating a potential vitamin C deficiency, it can occur before the onset of clinical symptoms of vitamin C deficiency. 3 Determination of vitamin C content in urine: affected by blood concentration. The path of human vitamin C is urine, which is only discharged from the urine when the storage of vitamin C in the body is saturated. When the plasma vitamin C concentration drops, the renal tubules can absorb a portion of the original urine. Not suitable for the crowd There is usually no special population. Adverse reactions and risks Excessive use can cause adverse reactions: daily consumption of 1 ~ 4g, can cause diarrhea, rash, gastric acid, gastric juice reflux, there are fashion urinary calculi, increased urinary oxalate and urate excretion, deep vein thrombosis Intravascular hemolysis or coagulation, sometimes leading to decreased white blood cell phagocytosis. When the daily dosage exceeds 5g, it can cause hemolysis, and the severe one can be fatal. When a pregnant woman takes a large dose, it may cause scurvy in infants.