Obesity and
severe obesity constitute growing serious health problems reaching epidemic proportion in most countries. Interactions and relationships between
obesity and bone tissue and its metabolism are complex but are more and more studied and recognized.
Obesity is associated with an altered hormonal profile including particularly bone-regulating
hormones like
vitamin D.
Bariatric surgery procedures, thanks to their effectiveness to achieve therapeutic endpoints for comorbidities associated with
obesity, have had an increasing success. However, these surgeries by producing mechanical restriction and or
malabsorption syndrome lead to
nutritional deficiencies including
vitamin D. In this review, we aim to (1) discuss the
nutritional deficiency of
vitamin D in the obese, (2) to summarize the different surgical options in
bariatric surgery and to present the evidence concerning these procedures and their associated profile in
vitamin D post-operative insufficiency, (3) to present the different recommendations in clinical practice to prevent or treat
vitamin D deficiencies or insufficiencies in patients treated by
bariatric surgery and finally to introduce emerging assumptions on the relationship between
vitamin D, microbiota composition and circulating
bile acids. Impact statement
Obesity and
severe obesity constitute growing serious health problems reaching epidemic proportion in most countries with a prevalence increasing from 6.4 in 1975 to 14.9% in 2014. This present review summarizes currently available data on
vitamin D deficiencies in the obese population before and after
bariatric surgery. The important evidence emerging from our evaluation confirms that obese patients are at risk of multiple
nutritional deficiencies, especially
vitamin D deficiency, before
bariatric surgery. Our survey confirms that the precise role of the gut microbiome and its associated changes on the
vitamin D metabolism after the different
bariatric surgery procedures has not yet been studied. Furthermore, whether differences in the microbiota may alter the therapeutic responses to
vitamin D is not known.