Circulating concentrations of vitamins and associated metabolites vary due to factors such as diet, lifestyle, vitamin enrichment and food fortification practices, and supplement use.
Nordic study found that multivitamin supplement use is highest in the United States, followed by the Nordic region, Australia and finally the Asian region.
While vitamin B and lipid soluble vitamins were low in Asia, researchers found circulating concentrations of metabolites, inversely related to B vitamins involved in the one-carbon and kynurenine pathways, were high in Asians. The kynurenine pathway is a metabolic pathway leading to the production of nicotinamide adenine dinucleotide from the degradation of the essential amino acid tryptophan. Disruption in the pathway is associated with certain genetic disorders.
Circulating concentrations of vitamins and associated metabolites vary due to factors such as diet, lifestyle, vitamin enrichment and food fortification practices, and supplement use.
In some countries, food fortification with various vitamins has been implemented to correct identified deficiencies or to reduce disease risk.
The circulating vitamins include riboflavin, pridoxal 5’- phosphate, folate, vitamin B-12, all trans- retinol, 25- hydroxyvitamin D, alpha- tocopherol.
The study also explained that in Asia, China had no vitamin fortification during the sampling period, whereas Singapore started fortification with folic acid in 1998, and in Australia, only the fortification of cereals with retinol took place.
Additionally, low circulating vitamin D in Asians was suggested to be related to skin pigmentation and the cultural avoidance of sun exposure.
