A recent study published by the journal of Obesity Surgery showed that obese patients in the northern climate undergoing roux-en-y gastric bypass benefited from vitamin D supplementation.
Individuals who undergo roux-en-y gastric bypass (RYGB) surgery are at an increased risk for micronutrient deficiencies, including low vitamin D levels. In fact, one study showed that vitamin D status steadily drops post RYGB surgery, in spite of vitamin D supplementation.
Currently, there is a lack of research investigating the incidence of vitamin D deficiency in bariatric patients located in the northern climate, where UVB exposure is limited.
In a recent study conducted in Wisconsin (latitude 43ᵒ N), vitamin D status was measured in 134 participants prior to RYGB surgery in order to determine the frequency and predictors of vitamin D deficiency (<30 ng/mL) in obese patients located in the northern climate. They found that 64% of patients were vitamin D deficient, and that vitamin D status was significantly affected by seasonality and the number of comorbidities present.
The researchers evaluated the effectiveness of high dose vitamin D supplementation in preventing hypovitaminosis D within the first year post RYGB surgery. Of the 60 remaining patients who followed up, vitamin D sufficiency was obtained in 62.5% of individuals. This appeared as a dose response relationship, with the most significant increase of 25(OH)D levels in those who supplemented with at least 2,000 IU of vitamin D.
The researchers concluded,
“Postoperatively, oral supplementation with at least 2000 IU per day of vitamin D will increase serum 25(OH)D concentrations in a dose response relationship for most of these patients.”