VITAMIN D DEFICIENCIES

• US 20110233395A1
• Filed: 02/07/2011
• Published: 09/29/2011
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic)
• Original Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic)
• Inventors: Taylor, Robert L., Singh, Ravinder J., Grebe, Stefan
• Granted Patent: US 8,349,613 B2
• Time in Patent Office: Days
• US Class Current: 250/282
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: G01N 33/82 involving vitamins or their receptors
• CPC Class Codes: H01J 49/0027 Methods for using particle spectrometers
• CPC Class Codes: Y10T 436/20 Oxygen containing
• CPC Class Codes: Y10T 436/203332 Hydroxyl containing
• CPC Class Codes: Y10T 436/212 Aromatic
• CPC Class Codes: Y10T 436/24 Nuclear magnetic resonance, electron spin resonance or other spin effects or mass spectrometry

Abstract

Methods for determining the amount of vitamin D compounds in a sample are provided. The methods can employ LC-MS/MS techniques and optionally the use of deuterated internal standards. Methods for diagnosing vitamin D deficiencies are also provided.

Claims

1-25. -25. (canceled)

26. A method for monitoring a vitamin D replacement therapy in a mammalian patient comprising:

a) obtaining a biological sample from the mammalian patient, wherein the mammalian patient has received at least one dose of a vitamin D replacement therapy;

b) determining an amount of 25-hydroxyvitamin D2 in a sample derived from the mammalian patient'"'"'s biological sample, wherein the determining comprises using a mass spectrometry technique to detect underivatized 25-hydroxyvitamin D2; and

c) comparing the amount of 25-hydroxyvitamin D2 in the sample with a range for 25-hydroxyvitamin D2 expected for the replacement therapy, wherein a lower than expected amount of 25-hydroxyvitamin D2 relative to the range expected is indicative of patient non-compliance with the therapy, malabsorption of vitamin D supplements, or resistance to 25-hydroxyvitamin D2.

27. The method of claim 26, wherein the mass spectrometry technique comprises a LC-MS/MS technique and wherein the LC-MS/MS technique comprises the use of a triple quadrupole instrument in Multiple Reaction Monitoring (MRM), positive-ion mode.

28. The method of claim 26, further comprising determining an amount of 25-hydroxyvitamin D3 in the sample.

29. The method of claim 26, wherein the amount of 25-hydroxyvitamin D2 is determined simultaneously with an amount of 25-hydroxyvitamin D3 in a single sample derived from the mammalian patient'"'"'s biological sample, wherein the determining comprises using a mass spectrometry technique to detect underivatized 25-hydroxyvitamin D2 and underivatized 25-hydroxyvitamin D3 in the single sample, wherein the mass spectrometry technique comprises a LC-MS/MS technique and wherein the LC-MS/MS technique comprises the use of a triple quadrupole instrument in Multiple Reaction Monitoring (MRM), positive-ion mode.

30. The method of claim 27, wherein the LC-MS/MS technique comprises a Q1 scan tuned to select a precursor ion that corresponds to the [M+H+] of 25-hydroxyvitamin D2.

31. The method of claim 26, wherein the mammalian patient is a human.

32. The method of claim 27, wherein the biological sample is a blood, urine, lachrymal, plasma, serum, or saliva sample.

33. The method of claim 27, wherein the LC-MS/MS technique comprises atmospheric pressure chemical ionization.

34. The method of claim 29, wherein the LC-MS/MS technique comprises a Q1 scan tuned to select, independently, precursor ions that correspond to the [M+H+] of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3.

35. The method of claim 27, wherein the LC-MS/MS technique comprises monitoring an MRM precursor-product ion pair transition having m/z values of 413.0/395.3 for 25-hydroxyvitamin D2.

36. The method of claim 29, wherein the LC-MS/MS technique comprises monitoring MRM precursor-product ion pair transitions having m/z values of 401.4/383.3 for 25-hydroxyvitamin D3 and 413.0/395.3 for 25-hydroxyvitamin D2.

37. The method of claim 26 or claim 29, further comprising using an internal standard selected from the group consisting of a deuterated derivative of 25-hydroxyvitamin D3 and a deuterated derivative of 25-hydroxyvitamin D2.

38. The method of claim 26, wherein the deriving of the single sample from the mammalian patient'"'"'s biological sample comprises removing interfering components from the mammalian patient'"'"'s biological sample.