We analyze how the column density of hydrogen atoms in the H i regions, observed in dark matter halos of a number of galaxies, can be determined. Specifically we study how the determination of the column density of hydrogen atoms from the observed astrophysical data would be affected by the possible presence of the Second Flavor of Hydrogen Atoms (SFHA), whose existence had been previously demonstrated in four different types of atomic experiments and had helped in explaining two puzzling astrophysical observations: the anomalous absorption in the 21 cm line from the early Universe and the smoother, less clumpy distribution of dark matter in the Universe than predicted by Einstein's gravity. By a model example we demonstrate that the neglect of the SFHA leads to the overestimation of the column density of hydrogen atoms in dark matter halos by about 30%. We perform these relatively simple estimates just to get the message across and to motivate further corresponding theoretical and experimental studies.