Blood normal ranges

Although it is being found that vitamin D metaboUtes play a role ia many different biological functions, metaboHsm primarily occurs to maintain the calcium homeostasis of the body. When calcium semm levels fall below the normal range, 1 a,25-dihydroxy-vitainin is made when calcium levels are at or above this level, 24,25-dihydroxycholecalciferol is made, and 1 a-hydroxylase activity is discontiaued. The calcium homeostasis mechanism iavolves a hypocalcemic stimulus, which iaduces the secretion of parathyroid hormone. This causes phosphate diuresis ia the kidney, which stimulates the 1 a-hydroxylase activity and causes the hydroxylation of 25-hydroxy-vitamin D to 1 a,25-dihydroxycholecalciferol. Parathyroid hormone and 1,25-dihydroxycholecalciferol act at the bone site cooperatively to stimulate calcium mobilization from the bone (see Hormones). Calcium blood levels are also iafluenced by the effects of the metaboUte on intestinal absorption and renal resorption. 

Criteria for initiation of drug treatment now take into consideration total cardiovascular risk rather than blood pressure alone, such that treatment is now recommended for persons whose blood pressure is in the normal range but still bear a heavy burden of cardiovascular risk factors. Thus, the role of simultaneous reduction of multiple cardiovascular risk factors in improving prognosis in hypertensive patients is stressed. In addition, more aggressive blood pressure goals are recommended for hypertensive patients with comorbid conditions such as diabetes mellitus or renal insufficiency. 

Euglycaemia, blood glucose concentration within the normal range e.g. fasting blood glucose 3.5 - 6.5 mmol/1 postprandial blood glucose 5-11 mmol/1. 

Hypoglycemia Abnormal decrease in blood glucose below the normal range. 

Leukocytosis Elevation of the white blood cell count above the normal range. 

In a particularly dramatic case of placebo-induced side effects, doctors at a hospital in Jackson, Mississippi, treated a young man who came into the emergency room, said to the receptionist, Help me, I took all my pills and then collapsed to the floor, dropping an empty prescription container. His blood pressure was abnormally low, and he was treated with intravenous fluids, which brought it back to within a normal range. The prescription bottle bore a label indicating that the medication was part of a clinical trial of antidepressants. Further investigation revealed that he had... 

Hypertension (blood pressure >140/90 mmHg) may be caused by an elevation in cardiac output or excessive vasoconstriction. Diuretics are used in these patients to reduce cardiac output. Assume that the hearts of these individuals are operating on the ascending portion of the cardiac function curve. As the plasma volume is reduced in response to treatment with diuretic drugs, venous return and preload are reduced, as are ventricular filling and stroke volume, and cardiac output, thus bringing blood pressure back within the normal range. 

Ammonia concentrations in arterial blood of patients with liver failure rise to 0.5-1 mmol/1, in contrast to the normal range of 0.01-0.02 mmol/1. Using positron emission tomography (PET see Ch. 58), increases of the cerebral metabolic rate for ammonia (CMRA), i.e. the rate at which ammonia is taken up and metabolized by the brain, have been reported in chronic liver failure [9]. Increased CMRA in chronic liver failure is accompanied... 

Human intake of total mercury from the diet normally ranges between 7 and 16 pg daily (Schumacher et al. 1994 Richardson et al. 1995). Fish consumption accounts for much of this exposure in the form of methylmercury 27% of the intake, and 40% of the absorbed dose. Intake of inorganic mercury arises primarily from foods other than fish, and is estimated at 1.8 pg daily with 0.18 pg absorbed daily (Richardson etal. 1995). In certain areas of India, blood mercury concentrations of people who ate fish were three to four times higher than non-fish eaters (Srinivasen and Mahajan 1989). In some countries, mercury in dental amalgams accounts for 2.8 pg daily, equivalent to as much as 36% of the total mercury intake and 42% of the absorbed dose (USPHS... 

Like other constituents of blood or serum, the deviation of their titer from the normal range may mean a number of things reduced intake or absorption, increased utilization, increased demand, increased excretion will all cause a decrease of titer, their opposites an increase. 

The so-called normal range of blood and serum vitamin levels is always derived from observations on healthy young subjects. How about a comparison with healthy old subjects, whose percentage in the population is steadily increasing Much may be learned about the cause of the decrease of physiological function and of the increased susceptibility to organic disease in old age, if the role of vitamins as parameter of these alterations were investigated with a view to preventive theory. 

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