Folic acid belongs to the group of water-soluble B vitamins and naturally exists in multiple forms in a wide variety of foods such as legumes, vegetables, liver, and milk (Iyer and Tomar, 2009; Lyon et al., 2020). It is involved in many biochemical reactions critical for cell division, such as purine and pyrimidine biosynthesis, DNA/RNA biosynthesis, and amino acid metabolism (Iyer and Tomar, 2009). Mammals cannot synthesize folic acid and thus they must acquire it from food. Although folic acid is ubiquitous in foods, folic acid deficiency still often occurs due to various causes such as unhealthy diet (Hildebrand et al., 2021; Iimura et al., 2022), disease-related malabsorption (Arcot and Shrestha, 2005), medication-related depletion (Arcot and Shrestha, 2005), or vitamin B12 deficiency (Fishman et al., 2000). Folic acid deficiency has been associated with several health problems, such as anemia (Carmel, 2005; Bailey and Caudill, 2012), cancer (Duthie, 1999), cardiovascular diseases (Wald et al., 2002), neural tube defects in newborns (van der Put et al., 2001), neuropsychiatric dysfunction (Shea et al., 2002), depression (Falade et al., 2021), inflammatory diseases (Suzuki and Kunisawa, 2015; Jones et al., 2019), and eye diseases (Sijilmassi, 2019). To prevent folic acid deficiency, its daily intake (400 μg/d) has been recommended for adults in the European Union, and its increased intake (600 μg/d) is advised for women before and during pregnancy (FAO/WHO, 2002; IOM, 2004). The New Zealand government mandated the fortification of non-organic wheat flour with folic acid in July 2021, and the UK government mandated the fortification of non-wholemeal wheat flour with folic acid in September 2021 (Haggarty, 2021).
Adult ; Animals ; Female ; Flour ; Folic Acid/metabolism* ; Folic Acid Deficiency/prevention & control* ; Food, Fortified ; Humans ; Infant, Newborn ; Mammals/metabolism* ; Pregnancy ; Triticum/metabolism*

Objective To identify the subcellular location of S AR S-CoV N protein in mammalian cells. Methods The gene fraction of SARS-CoV was cloned into the PGEFP-C1 plasmid to construct expression vecto r PGEFP-C1/N. The subcellular location of N in A549 and VeroE6 cells was observ ed under fluorescence microscope with the aid of transient transfection techniqu e. The expression of the fusion protein (GFP-N) was detected by Western blot. Results The PGEFP-C1/N was constructed. N protein was localiz ed in the cytoplasm of transfected cells and detected by Western blot. C onclusion N protein was localized in the cytoplasm of mammalian cells.