Regular intake of energy drinks and multivitamin supplements is associated with elevated plasma vitamin B6 levels in post-bariatric patients

Abstract

The aim of the present survey was to analyze plasma vitamin B6 levels in post-bariatric patients and to elucidate the causal factors associated with elevated plasma vitamin B6 levels. This is a retrospective analysis of electronic patient data of all post-bariatric patients evaluated at the endocrine outpatient clinic of the University Hospital Basel in 2017, for which plasma vitamin B6 values were assessed during regular follow-up visits. In total, 205 patients were included in the study, whereof a minority of 43% had vitamin B6 levels in the normal range. 50% of the patients had vitamin B6 levels up to fourfold higher than the upper normal limit and 7% had levels more than fourfold above the upper normal limit. Vitamin B6 deficiency was not observed in any patient. While multivitamin supplementation in general was associated with elevated plasma vitamin B6 levels, the highest vitamin B6 levels were found after biliopancreatic diversion (BPD) and in patients who reported daily energy drink intake. Elevated plasma vitamin B6 levels up to fourfold above the upper normal limit are common in postbariatric patients and are associated with regular multivitamin supplementation, while highly elevated plasma vitamin B6 levels were seen primarily upon regular energy drink intake. Thus, a regular follow-up of vitamin B6 plasma levels and critical evaluation of vitamin B6 supplementation, either as part of the multivitamin preparation or related to regular energy drink intake, is highly warranted and should be an integral part of the routine post-bariatric follow-up.

Figure 1

Study flow chart. RYGB Roux-en-Y gastric bypass, LSG laparoscopic sleeve gastrectomy, GB gastric banding, BPD biliopancreatic diversion, DS duodenal switch, n number of measurements.

Figure 2

Plasma vitamin B6 levels according to postoperative time interval from last bariatric surgery procedure. Vitamin B6 plasma levels at different time points after the last bariatric surgery procedure. Data are presented as median plasma levels and interquartile range. There was no significant difference between the groups. n number of vitamin B6 measurements in 205 patients in 2017.

Figure 3

Plasma vitamin B6 levels in patients after different bariatric surgery procedures. Data are presented as median plasma vitamin B6 levels and interquartile range (IQR) for each bariatric surgery procedure. Mean values were 176 nmol/l (IQR 104–205), 161 nmol/l (IQR 87–186), 110 nmol/l (IQR 88–132), and 347 nmol/l (IQR 102–577) in patients with Roux-en-Y gastric bypass (RYGB), laparoscopic sleeve gastrectomy (LSG), gastric banding (GB), and biliopancreatic diversion (BPD). Kruskal–Wallis-Test for intergroup comparison was significant (p-value 0.033). Level of significance between RYGB and LSG was calculated with Mann–Whitney U-test and is indicated in the graph with horizontal bar. Level of significance was not calculated for differences between gastric bypass (GB) or biliopancreatic diversion (BPD) due to low sample size. n number of plasma vitamin B6 measurements in 205 patients in 2017.

Figure 4

Plasma vitamin B6 levels and multivitamin supplementation intake in post-bariatric patients. (A) Presented are median plasma vitamin B6 levels and interquartile ranges (IQR) in patients with regular multivitamin (MV) intake (137 nmol/l, IQR 99–213) compared to patients who reported no regular multivitamin supplementation (101 nmol/l, IQR 73–153). (B) Plasma vitamin B6 levels in patients with recorded intake of the most common multivitamin compounds compared to those with recorded intake of multivitamin supplements without specification of the name of the compound (“unspecified”). Data are presented as median and interquartile ranges. Mean values were 145 nmol/l (IQR 102–172), 216 nmol/l (IQR 99–285), 210 nmol/l (IQR 101–221), and 202 nmol/l (IQR 96–241) in patients taking “Centrum von A bis Zink” (vitamin B6 content: 2 mg per serving), “Supradyn energy” (vitamin B6 content: 4 mg per serving), “Actilife all in one Depot” (vitamin B6 content: 1.4 mg per serving), and unspecified multivitamin compounds, respectively. Kruskal–Wallis-Test for intergroup comparison was not significant (p-value 0.28). Level of significance between two groups was calculated with Mann–Whitney U-test and is indicated in the graph with horizontal bars. n number of plasma vitamin B6 measurements in 205 patients in 2017.

Figure 5

Plasma vitamin B6 levels in postbariatric patients with documented energy drink consumption. Vitamin B6 plasma level measurements in patients (n = 12) with reported energy drink intake compared to patients without documented energy drink intake (n = 193). Data are presented as median with interquartile range. Level of significance between the two groups was calculated with Mann–Whitney U-test. n number of plasma vitamin B6 measurements in 205 patients in 2017.