Introduction. The aim of our research is to determine the breakdown value of
vitamin B12 in the blood that causes mild cognitive impairment. Material and
Methods. Two hundred respondents participated in this research. Using
screening tests, mild cognitive impairment was found in 50 patients, while
in 150 patients the cognitive function was preserved. Borderline values and
units of vitamin B12 concentration were determined according to the
standards of the local laboratory and their reference values ranged from
138.00 to 652.00 pmol/l. Results. Using the t-test for independent samples,
it was determined that there was a statistically significant difference in
the values of vitamin B12 in relation to whether or not the respondents had
mild cognitive impairment (? = 0.000), i.e. that respondents with mild
cognitive impairment - 225.66 had significantly lower values of vitamin B12
than those without mild cognitive impairment - 421.06. The statistic
analysis revealed that the area under the receiver operating characteristic
curve was significantly above 0,5 (0.968) and this result was statistically
significant (? < 0.0005). The breakdown value of vitamin B12 was determined
as the maximum product between sensitivity and specificity. Conclusion. In
this research, we determined that there was a statistically significant
difference in the values of vitamin B12 in relation to whether or not the
respondents had mild cognitive impairment. Being a significant risk factor
for mild cognitive impairment, we defined the breakdown value of vitamin B12
which induces mild cognitive impairment of 300.5 pmol/l.