April 15, 2025: Several vitamin assays will change effective May 13, 2025. Please read on for more information on changes to Vitamin A, Serum; Vitamin E, Serum and CSF; Vitamin Profile; Beta-Carotene, Serum; and Vitamin E: Cholesterol Ratio for Bovine Serum.
New Method for Vitamins A and E, Vitamin Profile
Effective May 13, 2025, the MSU VDL will transition measurement of vitamins A and E to a new method. Historically we have utilized UPLC with photodiode array (PDA) for vitamin analysis. Moving forward, we are shifting to UPLC tandem mass spectrometry, better known as LC-MS/MS. This change affects the following assays:
- Vitamin A (retinol), Serum (50208)
- Vitamin E, Serum (50212)
- Vitamin E, CSF (50256)
- Vitamin Profile (50229)
Clients will notice a subtle shift in reference intervals for Vitamins A and E due to the increased sensitivity and specificity of the LC-MS/MS instrument used. Prices for these vitamin A and E assays will remain the same.
In the coming months, we will transition the following assays to LC-MS/MS as well: Vitamin E, Tissue (50211), Feed (50210), and Other (50213); Vitamin A, Tissue (50207), Feed (50206), and Other (50209). We will provide updates when these changes occur.
Discontinuing Measurement of Beta-Carotene in Serum
Because of the limited clinical utility of beta-carotene in serum, that assay (50217) will no longer be available as a stand-alone and will not be included in the serum vitamin profile (50229) effective May 13, 2025. The price for the vitamin profile will be adjusted to reflect this change.
Beta-Carotene, Feed (50216) will remain available.
Discontinuing Measurement of Vitamin E: Cholesterol Ratio in Bovine Serum
As part of the transition to a new method for measuring vitamin E in serum effective May 13, 2025, we will no longer measure cholesterol in bovine samples submitted for Vitamin E, Serum (50212) or the Vitamin Profile (50229). This change will reduce turn-around times.
Cholesterol (10391) can be ordered separately when clinically relevant.
Why are we making this change? Historically, the MSU VDL provided bovine serum vitamin E concentrations in the context of cholesterol concentrations as a ratio. Cholesterol is a relative indicator of serum lipoprotein concentrations which do influence vitamin E status particularly at varying stages of lactation. However, recent research has concluded that while the adjustment of vitamin E to cholesterol increases accuracy of assessment, it does not enhance its biomarker function with respect to prediction of disease.