Objective: to assess the concentration of magnesium and potassium in the hair and their intake from food in medical workers of mobile ambulance teams working in the Northern region. The elemental status and daily diets of 110 medical workers of Khanty-Mansiysk were studied: 54 ambulance teams with an irregular rhythm of professional activity (10 or more night shifts per month) and 56 – out-patient shifts (day shift work). There was a signifi cant decrease in the concentration of Mg (p=0.005) and K (p=0.0004) in the hair of the fi eld ambulance personnel compared to the health workers of the clinic. The defi cit of varying severity of magnesium was revealed in 50 %, and potassium in almost 67 % of the field ambulance personnel and much less in health workers of the out-patient department: magnesium defi ciency – in 30 %, and potassium in 29 %. Almost the same defi cit was observed in dietary intake: magnesium (82-80,3 % AUP) and potassium (86,4-85,9 % AUP). The results of the study indicate professional changes in the micro nutrient status of health workers with an irregular rhythm of professional activity living in the Northern region, that must be corrected with the help of vitamin and mineral complexes and enriched food products.