What Are the Micronutrient Deficiencies Responsible for the Most Common Nutritional Symptoms After Bariatric Surgery?

Many patients complain of nutritional symptoms after bariatric surgery (BS), including hair loss, cramps, and paresthesia, but their link with biological alterations has been poorly studied.

To assess in a large cohort of subjects the relationship between nutritional symptoms and biological deficits both in the short term (ST ≤ 1 year) and long term (LT ≥ 3 years) after the 2 most common procedures, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

Nutritional symptoms and biological parameters (including vitamins, minerals, and protein parameters) were prospectively recorded. All subjects with complete clinical and biological assessments from 2011 to 2018 were included.

After BS, 555 subjects were studied in the ST (50% RYGB) and 494 in the LT (79% RYGB); multivitamin intake was 97% and 78%, respectively. The proportion of patients with hair loss decreased from 65 (ST) to 35% (LT) (p < 0.001). In contrast, cramps increase from 7 to 32% and paresthesia from 11 to 18% (p < 0.001). No significant difference was found between SG and RYGB. In subjects with hair loss, blood parameters of protein and iron metabolism were significantly lower than in subjects without hair loss, both in the ST and LT. In contrast, neither zinc nor group B vitamin levels were significantly different. None of the nutritional parameters tested was clearly associated with cramps and paresthesia.

After BS, the most frequent nutritional symptom is hair loss, essentially linked to iron and protein deficiencies. The causes of other nutritional symptoms are less clear and probably more heterogeneous.