See the Folate section of the B Vitamin Supplements Review for details
Reputable suppliers align voluntarily with ICH Q7 (International Council for Harmonisation guideline for GMP of active pharmaceutical ingredients) and ISO 9001 quality systems, with analytical methods referenced to European or US Pharmacopoeia monographs
But even at $/, would still require an API worth $5.32/tablet far beyond the range of commercial feasibility in GCC
J Immunol 173:28596, PMID: 15210786 DAlessio M, De Nicola M, Coppola S, Gualandi G, Pugliese L, Cerella C, Cristofanon S, Civitareale P, Ciriolo MR, Bergamaschi A, Magrini A, Ghibelli L (2005) Oxidative Bax dimerization promotes its translocation to mitochondria independently of apoptosis