1,25-dihydroxyvitamin D-3 is the active metabolite of vitamin D-3, and
has been found to play important roles in mineral balance and immunol
ogical regulation. Recently, 1,25-dihydroxyvitamin D-3 and similar syn
thetic analogs in development have been found to possess potential the
rapeutic values in the treatment of proliferative diseases, including
leukemia, breast cancer, and psoriasis. Current methods for the analys
is of these compounds may either lack the necessary sensitivity (i.e.,
UV detection) or specificity (i.e., receptor binding assay). In addit
ion, the synthetic analogs developed to date have nor been found to un
iformly bind with receptors in binding assays, a property that may ren
der them to be difficult for measurement at the trace levels. Methods
utilizing mass spectrometry (MS) have been used for either structural
identification or quantification. Electron impact ionization has been
the technique of choice for structural analysis, whereas newer ionizat
ion techniques have been utilized for the quantification of metabolite
s, often in conjunction with on-line separation. In this review, MS an
d non-MS based methods for vitamin D analysis will be discussed, with
an emphasis on the former. Historical perspectives, the present state,
and the future role of MS in vitamin D research will be discussed. (C
) 1996 John Wiley & Sons, Inc.