Vitamin B12 absorption judged by measurement of holotranscobalamin, active vitamin B12: evaluation of a commercially available EIA kit.
Summary of "Vitamin B12 absorption judged by measurement of holotranscobalamin, active vitamin B12: evaluation of a commercially available EIA kit."
Abstract Background: Active vitamin B12 absorption is followed by an increase in holotranscobalamin (holoTC) upon loading with a high physiological dose of the vitamin (the CobaSorb test). This study evaluates the use of a newly launched EIA kit for measurement of holoTC (active B12) in relation to the CobaSorb test. Methods: Intra-assay imprecision and linearity of the EIA kit was examined, employing serum pools of increasing holoTC concentrations. For the CobaSorb test, holoTC was measured before and after loading with 3-times 9 μg of vitamin B12 employing both the in-house ELISA and the EIA kit (n=25). Results: The EIA kit showed an intra-assay CV between 2.2% and 5.8% for holoTC values ranging from 21 to 80 pmol/L. Employing diluted serum samples resulted in spurious high values of holoTC. The EIA kit performed well in relation to the CobaSorb test and classified the patients studied as capable of absorbing vitamin B12 (n=10) or not (n=15), as did the in-house ELISA. Conclusions: The Active B12 (holoTC) EIA kit proved suitable for use with the CobaSorb test, but not for analysis of diluted serum samples.
Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark.
This article was published in the following journal.
Name: Clinical chemistry and laboratory medicine : CCLM / FESCC
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21995605
- DOI: http://dx.doi.org/10.1515/CCLM.2011.754
Abstract There has been renewed interest in vitamin D since numerous recent studies have suggested that besides its well-established roles in bone metabolism and immunity, vitamin D status is inversel...
Vitamin K (phytonadione) is a commonly used first-line reversal agent for vitamin K antagonist (VKA) therapy in patients presenting with a supratherapeutic international normalized ratio (INR) with or...
Vitamin D is essential for calcium absorption and for maintaining bone health in the pediatric population. Vitamin D deficiency may develop from nutritional deficiencies, malabsorption, enzyme-inducin...
Vitamin D, a fat-soluble prohormone, is synthesised in response to sunlight. Vitamin D requires two metabolic conversions, 25-hydroxylation in the liver and 1alpha-hydroxylation in the kidney, to beco...
In the present study the design of the vitamin B12 absorption test, CobaSorb, is further optimised. We investigate which test – measurement of holotranscobalamin or cobalamins – could ...
Vitamin B12 is an essential nutrient for normal DNA-synthesis and must be supplied by animal products. Vitamin B12 deficiency may cause anemia and irreverible neurological damage. Laborato...
When people eat a meal, some, but not all of the calcium in that meal is absorbed, that is, moved into the bloodstream. When the skin is exposed to sunlight during summer months, Vitamin D...
From previous studies it appeared that menaquinone-7 (MK-7) is the most effective form of vitamin K. The Japanese soya product natto is one of the richest food sources of MK-7. However, th...
The purpose of this study is to answer the following questions: Does vitamin D increase calcium absorption, bone mass and muscle mass and function in women past menopause who have mildly l...
Medical and Biotech [MESH] Definitions
A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)
A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.
9,10-Secoergosta-5,7,10(19),22-tetraene-3,25-diol. Biologically active metabolite of vitamin D2 which is more active in curing rickets than its parent. The compound is believed to attach to the same receptor as vitamin D2 and 25-hydroxyvitamin D3.
A synthetic naphthoquinone without the isoprenoid side chain and biological activity, but can be converted to active vitamin K2, menaquinone, after alkylation in vivo.
A family of phylloquinones that contains a ring of 2-methyl-1,4-naphthoquinone and an isoprenoid side chain. Members of this group of vitamin K 1 have only one double bond on the proximal isoprene unit. Rich sources of vitamin K 1 include green plants, algae, and photosynthetic bacteria. Vitamin K1 has antihemorrhagic and prothrombogenic activity.