Oct. 22, 2024
Multiple sources have noted that some patients with gastroparesis (Gp) have low levels of vitamin D. However, studies exploring the relationships of vitamin D deficiency with Gp symptoms and gastric neuromuscular dysfunction are scarce.
To shed further light on this topic, a team of researchers that included Pankaj J. Pasricha, M.B.B.S., M.D., sought to take a closer look at the prevalence of vitamin D levels in patients with Gp. Dr. Pasricha is a gastroenterologist and researcher at Mayo Clinic in Arizona.
According to Dr. Pasricha and co-authors, the researchers' primary goal was to determine the prevalence of low vitamin D levels in patients with Gp and to explore relationships among vitamin D levels, symptoms, gastric emptying rates and gastric myoelectrical activity (GMA) in response to the water load satiety test (WLST). The results of this study were published in Digestive Diseases and Sciences in 2024, with Dr. Pasricha serving as corresponding author.
Methods
The study cohort consisted of 513 patients with Gp symptoms for at least 12 weeks who were enrolled in the Gastroparesis Clinical Consortium Registry. This group of 513 patients contained two subgroups: 376 (74%) patients with delayed gastric emptying and 137 (26%) patients with normal gastric emptying.
Study participants underwent a history and physical exam and completed the following assessments:
- The Gastroparesis Cardinal Symptom Index (GCSI).
- The gastroduodenal disorder section of the Rome III Diagnostic Questionnaire for Adult Functional GI Disorders.
- Electrogastrography and water load satiety testing (WLST) to record gastric myoelectrical activity (GMA), expressed as percentage distribution of activity in normal and dysrhythmic ranges.
- Gastric emptying scintigraphy after an overnight fast to assess gastric neuromuscular function.
- Routine laboratory tests at enrollment, including serum 25-hydroxy vitamin D levels. The researchers defined vitamin D levels as follows: normal, ≥ 30 ng/mL; low, < 30 ng/mL; deficient, < 20 ng/mL; and insufficient, 20 to < 30 ng/mL.
Results
"Overall, we established that there is a high prevalence of vitamin D insufficiency or deficiency in patients with gastroparesis, and this correlates with some symptoms such as nausea. Another important finding that we saw was a possible biological mechanism in the association between low D levels and gastric dysrhythmia indicating dysfunction of interstitial cells of Cajal, which is a known pathophysiological feature in these disorders."
- Vitamin D levels were low (< 30 ng/ml) in 288 of the 513 (56.1%) patients with Gp symptoms.
- Vitamin D levels also were low in 206 of the 376 (54.8%) of patients with delayed gastric emptying and in 82 of the 137 (59.9%) patients with normal gastric emptying.
- Low vitamin D levels in both patient subgroups were associated with increased nausea and vomiting, but not with fullness or bloating subscores.
- Low vitamin D levels in patients with delayed gastric emptying were associated with greater meal retention at four hours (36% retention) compared with meal retention among patients with Gp who had normal vitamin D levels (31% retention).
- Low vitamin D levels in patients with normal gastric emptying was associated with decreased normal 3 cpm GMA before WLST and increased tachygastria after WLST.
"Overall, we established that there is a high prevalence of vitamin D insufficiency or deficiency in patients with gastroparesis, and this correlates with some symptoms such as nausea," says Dr. Pasricha. "Another important finding that we saw was a possible biological mechanism in the association between low D levels and gastric dysrhythmia indicating dysfunction of interstitial cells of Cajal, which is a known pathophysiological feature in these disorders."
Next steps
Although this study has shown a strong association with some symptomatic and physiological measures, Dr. Pasricha notes that establishing causality will require conducting a therapeutic trial.
"There are few effective therapies for gastroparesis and related disorders," explains Dr. Pasricha. "In theory, if future studies validate these findings beyond association, then restoration of vitamin D may provide a simple and safe way to provide at least some relief from nausea in these patients. It also would be interesting to see observational studies that monitor the change in nausea in response to vitamin D replacement."
For more information
Koch KK, et al. Low vitamin D levels in patients with symptoms of gastroparesis: Relationships with nausea and vomiting, gastric emptying and gastric myoelectrical activity. Digestive Diseases and Sciences. 2024;69:2904.
Refer a patient to Mayo Clinic.