Similarities of water-soluble vitamin components among non-prescription pharmaceutical vitamin products generally available on the domestic market

Similarities among non-prescription pharmaceutical vitamin products generally available in community pharmacies were examined based on their vitamin components, and a chart was constructed to diŠerentiate products to assist in appropriate product choice. In the analysis of the similarities, two hundred and seventy-six data entries on vitamin products were extracted from the database on the package inserts of the pharmaceutical products provided by the Pharmaceuticals and Medical Devices Agency, and they were reviewed for the amounts of vitamins they contained, in which the B vitamins, or vitamin B₁, B₂, B₆, B₁₂, and niacin, were considered as well as vitamins C and E. Pantothenic acid and_L-Cysteine that are frequently used in combination with those vitamins are also taken into consideration. The data entries were then processed by classical multi-dimensional scaling to evaluate the inter-product similarities. As a result, it was shown that the products categorized as pharmaceutical nutrients and tonics containing vitamins (NTcV) are similar to one another, reflecting the fact that they are less characteristic regarding their vitamin components. As for the products in other categories, they were generally found to be featured for their unique content of vitamin components, and thereby, each category includes products with a wide range of variation. It was also indicated that some products categorized as vitamin B₁, B₂, and C products are less distinguishable from those categorized as NTcV. These findings will assist pharmacists to decide on an appropriate product for a customer following consultation.