Vitamin diagnostic tests

Rule out vitamin B]2 and folate deficiency Rule out hypothyroidism with thyroid function tests Blood cell counts, serum electrolytes, liver function tests Other diagnostic tests... 

There is, moreover, the field of hypervitaminoses, which has been explored for the fat-soluble vitamins, but hardly touched in the water-soluble vitamins. The production of combined system disease by folic acid therapy of pernicious anemia belongs to this group, but many more instances wait to be recognized. The indiscriminate use of polyvitamin preparations by poorly informed clinicians is bound to mask such states and to delay their discovery. Also, the use of flushing doses of vitamins in diagnostic tests may cause acute hypervitaminoses. 

Vitamin status can be assessed by a direct test for the levels of 25-(OHin the serum, This competitive binding test involves three components (1) a serum sample, (2) radioactive 25-hydroxy[ Hjvitamin Dj, and (3) vitamin D-binding protein. The source of vitamin D-binding protein may be sheep serum. The functional tests for deternrination of vitamin D irvdude the diagnostic tests for rickets and osteomalacia. A test for osteomalacia, for example, may include measurement of the width of the osteoid in a bone biopsy. The osteoid is described later. 

Cobalt has no confirmed nutritional role in mammalian organisms aside from its participation in the corrin ring structure of cobalamins (vitamin B12). Nonetheless, inorganic cobalt is absorbed by the intestine. That this absorption pathway was shared with iron was first suggested by the observation of a mineral-mineral competition 42). The use of radioisotopes of iron in diagnostic tests of absorption for characterizing iron nutrition in human subjects has been advanced (43-45). An excellent correlation between absorption of radioiron and radiocobalt has been reported (43-45). 

The principal diagnostic test for excessive exposure of bromadiolone is markedly reduced prothromibin activity, and therapy is directed at correcting this by the administration of vitamin K. ... 

The deoxyuridine suppression test measures the effect of prior addition of deoxyuridine on the uptake of radiolabeled thymidine into the DNA of cultured bone marrow cells, peripheral blood lymphocytes, or whole blood. Normal samples that contain vitamin B12 can convert deoxyuridine to thymidine and therefore do not take up as much thymidine. Samples from patients who are deficient in vitamin B12 show less suppression than in normal patients. Because it is relatively time consuming, the deoxyuridine suppression test is not widely available for use as a diagnostic test. ... 

Diagnostic tests Measuns vitamin C in white blood cells ( buffy coat )... 

The use of ELISA is broad and it finds applications in many biological laboratories over the last 30 years many tests have been developed and vahdated in different domains such as clinical diagnostics, pharmaceutical research, industrial control or food and feed analytics for instance. Our work has been to redesign the standard ELISA test to fit in a microfluidic system with disposable electrochemical chips. Many applications are foreseen since the biochemical reagents are directly amenable from a conventional microtitre plate to our microfluidic system. For instance, in the last 5 years, we have reported previous works with this concept of microchannel ELISA for the detection of thromboembolic event marker (D-Dimer) [4], hormones (TSH) [18], or vitamin (folic acid) [24], It is expected that similar technical developments in the future may broaden the use of electroanalytical chemistry in the field of clinical tests as has been the case for glucose monitoring. This work also contributes to the novel analytical trend to reduce the volume and time consumption in analytical labs using lab-on-a-chip devices. Not only can an electrophoretic-driven system benefit from the miniaturisation but also affinity assays and in particularly immunoassays with electrochemical detection. 

AU patients with a suspected low vitamin Bn level should be screened. Vitamin Bn values below 150 pg/mL in a patient with macrocytosis, hypersegmented polymorphonuclear leukocytes, peripheral neuropathy, or dementia, is diagnostic of Bn deficiency, even though the Schilling test results may be normal. About one-third of patients with pernicious anemia will not demonstrate macrocytosis if their condition is complicated by iron deficiency, thalassemia, or a predominant neurologic involvement. 

The evaluation of an optimal diagnostic threshold for active vitamin B12 was carried out by testing holoTC concentration on 250 selected serum specimens. Figure 28.3 shows weak correlation between holoTC and tBi2 levels on all specimens (r = 0.420). No correlation was found between holoTC and other metabolically correlated parameters (folate, homocysteine and creatinine). 

Diagnosis of a malabsorption syndrome is based on the results of absorption tests such as xylose absorption, fat absorption balance study, the Schilling test for vitamin 6-12 absorption, and the folic acid test. Also gastrointestinal x ray studies, small intestine biopsy, prothrombin time, and serum levels of vitamin A are useful diagnostic tools. 

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