Characterization and Quantitation of Vitamin B₁₂ Compounds in Various Chlorella Supplements

Abstract

Vitamin B was determined and characterized in 19 dried Chlorella health supplements. Vitamin contents of dried Chlorella cells varied from <0.1 μg to approximately 415 μg per 100 g of dry weight. Subsequent liquid chromatography/electrospray ionization-tandem mass spectrometry analyses showed the presence of inactive corrinoid compounds, a cobalt-free corrinoid, and 5-methoxybenzimidazolyl cyanocobamide (factor IIIm) in four and three high vitamin B-containing Chlorella tablets, respectively. In four Chlorella tablet types with high and moderate vitamin B contents, the coenzyme forms of vitamin B 5'-deoxyadenosylcobalamin (approximately 32%) and methylcobalamin (approximately 8%) were considerably present, whereas the unnaturally occurring corrinoid cyanocobalamin was present at the lowest concentrations. The species Chlorella sorokiniana (formerly Chlorella pyrenoidosa) is commonly used in dietary supplements and did not show an absolute requirement of vitamin B for growth despite vitamin B uptake from the medium being observed. In further experiments, vitamin B-dependent methylmalonyl-CoA mutase and methionine synthase activities were detected in cell homogenates. In particular, methionine synthase activity was significantly increased following the addition of vitamin B to the medium. These results suggest that vitamin B contents of Chlorella tablets reflect the presence of vitamin B-generating organic ingredients in the medium or the concomitant growth of vitamin B-synthesizing bacteria under open culture conditions.

Potential of Chlorella as a Dietary Supplement to Promote Human Health

“…The reported B 12 content of Chlorella products varies from <0.1 to 400 µg per 100 g of dry weight [58,59], consistent with that of the products shown in Table 3 (6-500 µg/100 g dry weight). Among Chlorella species, the B 12 content is much higher in C. pyrenoidosa than in C. vulgaris when grown under open culture conditions [59]. B 12 is not essential for the growth of these Chlorella species [59,60], suggesting that Chlorella cells absorb and accumulate large amounts of exogenous B 12 .…”

“…B 12 content is high in beef, pork, and chicken livers (approximately 25-53 µg/100 g fresh weight) [56] and in edible bivalves such as clams (approximately 60 µg/100 g fresh weight) [57]. The reported B 12 content of Chlorella products varies from <0.1 to 400 µg per 100 g of dry weight [58,59], consistent with that of the products shown in Table 3 (6-500 µg/100 g dry weight). Among Chlorella species, the B 12 content is much higher in C. pyrenoidosa than in C. vulgaris when grown under open culture conditions [59].…”

Human Intrinsic Factor Expression for Bioavailable Vitamin B12 Enrichment in Microalgae

“…As shown recently for Chlorella supplements [ 6 ], currently available eukaryotic microalgal supplements can contain varying amounts of B 12 . This is most likely due to different cultivation conditions altering the composition of the associated bacterial biofilms that are the original source of B 12 found in the supplements.…”

“…To counteract the lack of dietary B 12 intake, a wide range of supplements are commercially available. For instance, microalgal Chlorella supplements were found to contain amounts of B 12 varying from trace amounts up to 415 μg per 100 g dry weight [ 6 ].…”

Enhanced Vitamin B12 Production using Chlorella vulgaris

“…Some researcher scientists [9][10][11] have evaluated vitamin B12 content of C. vulgaris tablets but there was no specific research on enhancing vitamin B12 biosynthesis besides of biomass productivity. Therefore, an especial study with the aim of examining the microalgae growth and impact of the culture medium on the vitamin B12 production is required.…”