Proton pump inhibitors reduce the bioavailability of dietary vitamin C

Henry, E; Carswell, Anne; Wirz, Angela A.; Fyffe, V.; McColl, Kenneth E.L.

doi:10.1111/j.1365-2036.2005.02568.x

Cited by 48 publications

(34 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…PPIs and H2RAs, which are acid-suppressant drugs, are commonly prescribed as chronic preventive and therapeutic drugs for the treatment of peptic ulcers and gastroesophageal reflux disease. However, studies have reported that chronic administration of PPIs decreases vitamin C levels in gastric juices through hyposecretion and the instability of ascorbic acid, which is related to hypochlorhydria induced by potent acid suppression (31)(32)(33). Furthermore, chronic H2RA or PPI use has been shown to be associated with the development of serum vitamin B12 deficiency through PPI-associated malabsorption due to decreased release of vitamin B12 from ingested food (34)(35)(36).…”

Section: Discussionmentioning

confidence: 99%

Water-Soluble Vitamin Deficiencies in Complicated Peptic Ulcer Patients Soon after Ulcer Onset in Japan

Miyake

Akimoto

Kusakabe

et al. 2013

J Nutr Sci Vitaminol

View full text Add to dashboard Cite

SummaryWe investigated over time whether contemporary Japanese patients with complicated peptic ulcers have any water-soluble vitamin deficiencies soon after the onset of the complicated peptic ulcers. In this prospective cohort study, fasting serum levels of water-soluble vitamins (vitamins B1, B2, B6, B12, C, and folic acid) and homocysteine were measured at 3 time points (at admission, hospital discharge, and 3 mo after hospital discharge). Among the 20 patients who were enrolled in the study, 10 consecutive patients who completed measurements at all 3 time points were analyzed. The proportion of patients in whom any of the serum water-soluble vitamins that we examined were deficient was as high as 80% at admission, and remained at 70% at discharge. The proportion of patients with vitamin B6 deficiency was significantly higher at admission and discharge (50% and 60%, respectively, p,0.05) than at 3 mo after discharge (10%). In conclusion, most patients with complicated peptic ulcers may have a deficiency of one or more water-soluble vitamins in the early phase of the disease after the onset of ulcer complications, even in a contemporary Japanese population.

show abstract

Section: Discussionmentioning

confidence: 99%

Water-Soluble Vitamin Deficiencies in Complicated Peptic Ulcer Patients Soon after Ulcer Onset in Japan

Miyake

Akimoto

Kusakabe

et al. 2013

J Nutr Sci Vitaminol

View full text Add to dashboard Cite

show abstract

“…We, therefore, suggest that vitamin C supplements should be avoided in patients receiving proteasome inhibitor therapy. In particular, we recommend that patients who are under treatment with bortezomib should not take more than 500 mg of vitamin C. Specifically, it should be avoided at least 12 h before and after bortezomib treatment as the half-life of oral ascorbic acid in plasma is 10 h. 7,35 The transport and the accumulation of vitamin C depend on several mechanisms, including diet as well as modulating factors, such as proton pump inhibitors, 36 which increase gastric pH and reduce the stability and absorption of vitamin C; or dexamethasone, which induces sodium dependent vitamin C transporters and increases the accumulation of ascorbic acid, as shown in an osteoclastic cell model. 37 Importantly, our study shows that vitamin C supplementation decreases the efficacy of bortezomib treatment and outcome in vivo even at relatively low concentrations.…”

Section: Discussionmentioning

confidence: 99%

Ascorbic acid inhibits antitumor activity of bortezomib in vivo

et al. 2009

View full text Add to dashboard Cite

Earlier studies have shown that ascorbic acid (vitamin C) inhibits bortezomib-induced cytotoxicity against cancer cells in vitro. However, the clinical significance of vitamin C on bortezomib treatment is unclear. In this study, we examined whether daily oral intake of vitamin C inhibits antimultiple myeloma (MM) activities of bortezomib. Vitamin C, at orally achievable concentrations, inhibited in vitro MM cell cytotoxicity of bortezomib and blocked its inhibitory effect on 20S proteasome activity. Specifically, plasma collected from healthy volunteers taking 1 g/day vitamin C reduced bortezomibinduced MM cell death in vitro. This antagonistic effect of vitamin C against proteasome inhibitors is limited to the boronate class of inhibitors (bortezomib and MG262). In vivo activity of this combination treatment was then evaluated using our xenograft model of human MM in SCID (severe combined immune-deficient) mice. Bortezomib (0.1 mg/kg twice a week for 4 weeks) significantly inhibits in vivo MM cell growth, which was blocked by oral vitamin C (40 mg/kg/day). Therefore, our results for the first time show that vitamin C can significantly reduce the activity of bortezomib treatment in vivo; and importantly, suggest that patients receiving treatment with bortezomib should avoid taking vitamin C dietary supplements.

show abstract

“…Low levels of vitamin B12 are associated with both types of drugs, and proton-pump inhibitors reduce vitamin C levels. 16,17 It is likely that many more nutrients are affected. Indeed many different nutrients are needed for normal cognitive function.…”

Section: Act Notesmentioning

confidence: 99%

Medical Journal Watch: Context and Applications

Challem

2008

Alternative and Complementary Therapies

View full text Add to dashboard Cite

Proton pump inhibitors reduce the bioavailability of dietary vitamin C

Cited by 48 publications

References 22 publications

Water-Soluble Vitamin Deficiencies in Complicated Peptic Ulcer Patients Soon after Ulcer Onset in Japan

Water-Soluble Vitamin Deficiencies in Complicated Peptic Ulcer Patients Soon after Ulcer Onset in Japan

Ascorbic acid inhibits antitumor activity of bortezomib in vivo

Medical Journal Watch: Context and Applications

Contact Info

Product

Resources

About