Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

There are provided a urine testing apparatus and a urine testing method which can stabilize urine vitamins for several days and improve testing accuracy and convenience of a urine collection test of a subject. According to this urine testing apparatus, the inner wall surface of a urine collection storage container is coated with an aqueous citric acid solution or the like as a urine stabilizer. Alternatively, a dried or freeze-dried aqueous citric acid solution or the like as the urine stabilizer is stored in the urine collection storage container. On the other hand, according to the urine testing method of this invention, the aqueous citric acid solution or the like as the urine stabilizer is added to the collected urine sample, the vitamin concentration of at least 7 days after urine collection is stabilized to stabilize each urine vitamin for several days, thereby improving the convenience of the urine collection test of the subject. In particular, the urine concentrations of vitamins B can be stabilized to accurately test the nutrients lacking in the body of the subject.

There are provided a urine testing apparatus and a urine testing method which can stabilize urine vitamins for several days and improve testing accuracy and convenience of a urine collection test of a subject. According to this urine testing apparatus, the inner wall surface of a urine collection storage container is coated with an aqueous citric acid solution or the like as a urine stabilizer. Alternatively, a dried or freeze-dried aqueous citric acid solution or the like as the urine stabilizer is stored in the urine collection storage container. On the other hand, according to the urine testing method of this invention, the aqueous citric acid solution or the like as the urine stabilizer is added to the collected urine sample, the vitamin concentration of at least 7 days after urine collection is stabilized to stabilize each urine vitamin for several days, thereby improving the convenience of the urine collection test of the subject. In particular, the urine concentrations of vitamins B can be stabilized to accurately test the nutrients lacking in the body of the subject.

The invention discussed in this application relates to vitamin B12-based compounds that are useful as quantitative standards, particularly for the assessment of vitamin B12 deficiency.

The invention discussed in this application relates to vitamin B12-based compounds that are useful as quantitative standards, particularly for the assessment of vitamin B12 deficiency.

A composition is provided comprising a therapeutically active amount of vitamin K for administering to a subject as prophylactic for preventing or reducing the risk of developing severe disease or mortality by COVID-19 or a similar infectious disease, or as therapeutic for preventing said disease becoming more severe or reducing the severity of said disease. Also provided is a diagnostic test to estimate the risk of developing severe disease or mortality by COVID-19 or a similar infectious disease in a subject involving assessing vitamin K status in blood, serum or plasma of said subject.

The present invention addresses the problem of providing a method for measuring 25-hydroxy vitamin D and a measurement reagent, the method and the reagent being based on a competitive immunoassay. The present invention provides a reagent for measuring 25-hydroxy vitamin D based on a competitive immunoassay, which includes at least the following composition: (1) a Vitamin D derivative represented by the chemical formula (I) and/or (II), (2) an anti-25 hydroxy vitamin D antibody. In addition, the present invention provides a reagent for measuring vitamin D based on a competitive latex turbidimetric immunoassay (competitive LTIA) in which, in particular, a vitamin D derivative or an anti-25-hydroxy vitamin D antibody is immobilized on latex.

The present invention addresses the problem of providing a method for measuring 25-hydroxy vitamin D and a measurement reagent, the method and the reagent being based on a competitive immunoassay. The present invention provides a reagent for measuring 25-hydroxy vitamin D based on a competitive immunoassay, which includes at least the following composition: (1) a Vitamin D derivative represented by the chemical formula (I) and/or (II), (2) an anti-25 hydroxy vitamin D antibody. In addition, the present invention provides a reagent for measuring vitamin D based on a competitive latex turbidimetric immunoassay (competitive LTIA) in which, in particular, a vitamin D derivative or an anti-25-hydroxy vitamin D antibody is immobilized on latex.

A method of attenuating, treating or preventing cognitive aging in an individual who does not have dementia includes administering to the individual a therapeutically effective amount of a composition containing an omega-3 fatty acid, a nitric oxide releasing compound, Vitamin B12 and choline. The composition is administered in a daily dose that provides 0.1 to 50 times the recommended daily requirement (RDA) of Vitamin B12 per day, more preferably 0.1 to 40 times the recommended daily requirement (RDA) of Vitamin B12 per day and 0.01 to 10.0 times the recommended daily requirement (RDA) of choline. Optionally Vitamin B6 and/or Vitamin B9 can be included in the composition. The method can achieve a benefit that is one or more of decreasing brain atrophy, increasing or maintaining number of synapses, increasing amyloid-β phagocytosis, or decreasing or maintaining neuroinflammation in the non-demented individual. The method can prevent dementia in an individual at risk thereof, for example an elderly human.