Biochemical and dietary patterns of vitamin K and Magnesium pre-and post-sleeve surgery in morbidly obese Saudi males and females

Micronutrient deficiencies are known to be common among patients who undergo sleeve gastrectomy (SG), but changes in trace elements such as magnesium (Mg) and vitamin K remain under investigated, especially in Saudi Arabia where such surgical procedures are common. The present prospective study aims to fill this gap. A total of 51 (19 males, 32 females) out of 72 patients who underwent SG at King Fahad Medical Center, Riyadh, Saudi Arabia, were followed up for 12 months. Anthropometrics and information on dietary intake were collected. Blood samples were tested at baseline, 3 months, and 12 months post-SG. Circulating Mg was assessed using routine methods, while vitamin K and homologs (MK4 and MK7) were measured using liquid chromatography-mass spectrometry (LCMS). Dietary Mg intake was low for all participants in all time points, while 90% of all participants (91% females and 89.5% males) had low dietary vitamin K intake at baseline, reaching 100% in males and 94% in females after 12 months. In all participants, no significant changes were seen in circulating vitamin K and MK4 after 3 and 12 months of follow-up. No differences were seen between baseline serum Mg and after 3 months, while a significant increase was observed after 12 months, which was significantly higher than values obtained at baseline and 3 months (p<0.05). A significant decrease in serum MK7 was observed only in females after 3 months (p=0.017). Dietary intake of Mg and vitamin K is extremely low in patients who undergo SG. While a modest improvement in circulating Mg with no apparent fluctuations in vitamin K levels was observed in patients 1 year after SG, MK7 levels were seen to decrease over time only in females, which may have implications for bone and cardiovascular health, warranting further investigation and routine micronutrient screening. Whether the decrease in vitamin K homologs is associated with SG-related complications needs to be clarified in future investigations. Screening for dietary micronutrient deficiencies is encouraged for better management in patients who undergo SG.