Vitamin D levels in women and factors contributing to explain metabolic variations.

The elucidated metabolism of vitamin D in humans has been the support to explain the high involvement of this liposoluble vitamin in physiological functions. Clinical studies have associated levels of vitamin D metabolites with several disorders. Despite this knowledge, there is a controversy regarding the estimation of deficiency and the physiological and supraphysiological levels of vitamin D metabolites.

Profiling analysis of phospholipid fatty acids in serum as a complement to the comprehensive fatty acids method.

Fatty acids (FAs) are mostly found in blood as triglycerides, phospholipids (PLs) and cholesteryl esters. Determination of FAs is typically carried out in serum or plasma by a comprehensive method (known as the classical FAMEs method since FAs are determined as Fatty Acids Methyl Esters), which is based on liquid-liquid extraction, derivatization by transesterification, and determination by gas chromatography (GC) coupled to a suited detection technique. However, this method does not favor the determination of FAs that are chemically conjugated in PLs due to kinetics impediment.

Determination of glycerophospholipids in vegetable edible oils: Proof of concept to discriminate olive oil categories.

Glycerophospholipids (GPLs) constitute a chemical family within the saponifiable fraction of vegetable oils. GPLs have been scarcely studied in edible oils owing to the lack of sensitive and selective analytical methods. We have developed a method for identification, confirmation and relative quantitation of GPLs in vegetable oils.

Evaluation of short-term storage prior to analysis of vitamin D and metabolites in human serum by liquid chromatography coupled to tandem mass spectrometry.

Vitamin D has been widely determined in clinical trials to elucidate its biochemical involvement in a great number of pathologies. The analysis of vitamin D and its hydroxymetabolites in biofluids such as serum or plasma is a challenging task due to limitations associated to the low concentrations of some metabolites (typically, dihydroxymetabolites), methodological interferences, and the low stability of the compounds. Among these limitations, efforts have been targeted at optimizing instrumental improvements to develop more sensitive and selective methods, while the stability of vitamin D and metabolites has not been exhaustively evaluated.

Serum 25-hydroxyvitamin D and mammographic density in premenopausal Spanish women.

The role of vitamin D in mammographic density is still unclear. This study examines the association between serum 25-hydroxyvitamin D (25(OH)D) and mammographic density, overall and by specific women characteristics. DDM-Madrid is a cross-sectional study that recruited 1403 premenopausal women in a breast radiodiagnosis unit of Madrid City Council.