Despite various methodological schemas designed to categorize personality disorders, many issues occur with classifying a personality disorder because the theory and diagnosis of such disorders occur within prevailing cultural expectations; thus, their validity is contested by some experts on the basis of inevitable subjectivity. They argue that the theory and diagnosis of personality disorders are based strictly on social, or even sociopolitical and economic considerations. Classification and symptoms
The two latest editions of the major systems of classification are

the International Classification of Diseases (11th revision, ICD-11) published by the World Health Organization
the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition, DSM-5) by the American Psychiatric Association.The ICD is a collection of alpha-numerical codes which have been assigned to all known clinical states, and provides uniform terminology for medical records, billing, statistics and research. The DSM defines psychiatric diagnoses based on research and expert consensus. Both have deliberately aligned their diagnoses to some extent, but some differences remain. For example, the ICD-10 included narcissistic personality disorder in the group of other specific personality disorders, while DSM-5 does not include enduring personality change after catastrophic experience. The ICD-10 classified the DSM-5 schizotypal personality disorder as a form of schizophrenia rather than as a personality disorder. There are accepted diagnostic issues and controversies with regard to distinguishing particular personality disorder categories from each other. Dissociative identity disorder, previously known as multiple personality as well as multiple personality disorder, has always been classified as a dissociative disorder and never was regarded as a personality disorder.
Calcifediol has an elimination half-life of around 15 to 30 days.Calcifediol is further hydroxylated at the 1-alpha-position in the kidneys to form 1,25-(OH)2D3, calcitriol. This enzymatic 25(OH)D-1α-hydroxylase reaction is performed exclusively by CYP27B1, which is highly expressed in the kidneys where it is principally regulated by parathyroid hormone, but also by FGF23 and calcitriol itself. CYP27B1 is also expressed in a number of other tissues, including macrophages, monocytes, keratinocytes, placenta and parathyroid gland and extra-renal synthesis of calcitriol from calcifediol has been shown to have biological effects in these tissues.Calcifediol is also converted into 24,25-dihydroxycholecalciferol by 24-hydroxylation. This enzymatic reaction is performed by CYP24A1 which is expressed in many vitamin D target tissues including kidney, and is induced by calcitriol. This will inactivate calcitriol to calcitroic acid, but 24,25-(OH)2D3 may have some biological actions itself. Blood test for vitamin D deficiency
In medical practice, a  blood test for 25-hydroxy-vitamin D, 25(OH)D, is used to determine an individuals vitamin D status. The name 25(OH)D refers to any combination of calcifediol (25-hydroxy-cholecalciferol), derived from vitamin D3, and ercalcidiol (25-hydroxy-ergocalciferol), derived from vitamin D2. The first of these (also known as 25-hydroxy vitamin D3) is made by the body, or is sourced from certain animal foods or cholecalciferol supplements. The second (25-hydroxy vitamin D2) is from certain vegetable foods or ergocalciferol supplements. Clinical tests for 25(OH)D often measure the total level of both of these two compounds together, generally without differentiating.This measurement is considered the best indicator of overall vitamin D status.