The SULT1 family comprises of 9 members divided into 4 subfamilies (1A1, 1A2, 1A3, 1A4, 1B1, 1C1, 1C2, 1C3 and 1E1)
There is some evidence suggesting it may interfere with the efficacy of certain chemotherapy drugs or other medications processed by the liver
[Crossref] El-Saie LT1, Rabie AR, Kamel MI, Seddeik AK, Elsaie ML (2011) Effect of narrowband ultraviolet B phototherapy on serum folic acid levels in patients with psoriasis
Liver NASO B12 NASAL SPRAY should be used with caution in patients with liver problems
Additionally, the issue is exacerbated by traditional laboratories setting the 'normal' range too low, which may result in undiagnosed B12 deficiencies