Folates or vitamin B9, are crucial for maintaining health, and adequate intake is ensured
through food supplements, which traditionally use synthetic folic acid. In recent years, the
use of its active form – 5-methyltetrahydrofolate (5-MTHF), as calcium or glucosamine salt,
in food supplements is increasing, both of which exhibit several advantages. Since food
supplements are less strictly regulated compared to medicinal products, this master’s thesis
focused on determining the content and quality of supplements with 5-MTHF.
For this purpose, we used three previously developed methods (A, B and C) and validated
them in accordance with the ICH guideline. We optimized the extraction procedure and
determined a solvent mixture that ensured the stability of prepared samples (10 % methanol,
2 mM sodium hydroxide, 1 mM ethylenediaminetetraacetic acid, 0.24 g/L vitamin C).
Subsequently, the optimized extraction procedure and validated analytical methods, chosen
based on the complexity of the samples, were used to analyse the selected supplements. We
evaluated a total of 18 different supplements containing 5-MTHF, with which we aimed to
illustrate the current market situation. The presence of 5-MTHF was confirmed in 16
products, whereas in two products the content was below the detection limit. The determined
contents were compared with the declared values and assessed for compliance with the
European Commission guidelines, which define an acceptable range of 80–150 %. Seven
products (39 %) were below the lower limit, while none exceeded the upper limit.
Hereinafter, we classified the products according to their dosage form and type of 5-MTHF
salt to evaluate their potential impact on actual content. A total of 7 tablets, 5 capsules, 4
liquids, and 2 sachets were analysed. Tablets and capsules showed the highest conformity
with the declared values, while liquid formulations exhibited the highest deviations (75.0 %
below 80% of the declared value), likely due to vitamin instability in aqueous media. Among
both salts, 8 products containing the calcium form (66.7 %) were within the acceptable range,
compared to 2 products (40.0 %) with the glucosamine form. However, it is difficult to
conclude which form is intrinsically more stable, due to the lower number of glucosaminebased products, two of which were liquid formulations. Price–quality comparison revealed
no direct correlation between higher cost and better quality.
Based on the obtained results, it can be concluded that folate-containing food supplements
deserve greater attention, as they are primarily marketed to pregnant women – a vulnerable
population group for whom adequate folate intake is particularly important.
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