Environmental conditions and strenuous cognitive workload necessitate optimization of nutrition. This study aimed to evaluate the effectiveness of a predominantly plant-based product in improvement of the vitamin and mineral status of people engaged in intellectual labor. The formula for the product was developed after assessment of the said status and working conditions of the participants. The treatment group (n = 30) has been supplementing its diet with the product for 21 days, while the control group (n = 30) has not. The blood plasma levels of vitamins (B9 and B12, and 25(OH)D) and minerals (K, Na, ionized and total Ca, Fe, Mg, and P) were determined. By degree of strain, the considered occupations were classified as harmful strenuous work (class 3.2).  Initially, the level of vitamin B9 in each group was in the "low−normal" zone. Through the experiment, in the treatment group it increased by 3.2−3.8%, while in the control group the said level dropped by 3.7−3.9%; the level of vitamin B12  increased by 36.7−46.7% and decreased in 23.3−36.7%, respectively, and that of 25(OH)D increased by 3.0% (p = 0.02) and decreased by 3.3% (p = 0.03). The level of ionized calcium in the treatment group increased by 7.0% (p = 0.001) and decreased by 50.0−53.3% in the control group. Iron levels increased by 3.1% in 80% of the treatment group participants (p = 0.04), and sodium levels increased by 0.9% (p = 0.04), which was 46.7−60.0% higher than the baseline values; in the control group, sodium levels dropped by 23.3−26.7%. No significant changes were recorded for the levels of K, total Ca, P, Mg, but at the level of individual indicators we observed multidirectional changes.  Thus, the use of the multicomponent plant-based product demonstrates the promise of this approach for preventing vitamin and mineral deficiencies.