Ethnicity influences total serum vitamin B concentration: a study of Black, Asian and White patients in a primary care setting.

Aims: A growing body of evidence suggests that ethnicity and race influence vitamin B metabolism and status yet clinical awareness of this is poor, causing doubts regarding diagnosis and treatment. Moreover, deficiency and insufficiency cut-offs are universally applied for this test in most diagnostic settings. The objective of this study was to assess serum vitamin B concentrations in Black, Asian and White primary care patients in London, UK, particularly in patients of Black or Black British ethnic origin and establish if there is a need for specific reference ranges.

Laboratory assessment of vitamin K status.

Vitamin K is required for the ɣ-carboxylation of specific glutamic acid residues within the Gla domain of the 17 vitamin K-dependent proteins (VKDPs). The timely detection and correction of vitamin K deficiency can protect against bleeding. Vitamin K also plays a role in bone metabolism and vascular calcification.

Superwarfarin poisoning and its management.

Difenacoum is a long-acting superwarfarin-type anticoagulant that exerts its effect through inhibiting vitamin K 2,3-epoxide reductase. Inhibition of this enzyme leads to reduced bioavailability of the metabolically active form of vitamin K resulting in decreased production of vitamin K-dependent proteins including coagulation factors II, VII, IX and X. A 45-year-old woman with psychiatric illness presented with haematuria.

Urinary excretion of vitamin K metabolites in term and preterm infants: relationship to vitamin K status and prophylaxis.

Little is known about the metabolic turnover and excretion of vitamin K in healthy newborn infants and the metabolic consequences of prophylactic regimens designed to protect against vitamin K deficiency bleeding (VKDB). We measured the excretion of two urinary metabolites (≤ 24 h) of vitamin K (5C- and 7C-aglycones) in term infants before (n = 11) and after (n = 5) a 1000 μg i.m.