Dietary vitamin D supplementation does not reduce the incidence or severity of asbestos-induced mesothelioma in a mouse model

Our plain-English summary of Dietary vitamin D supplementation does not reduce the incidence or severity of asbestos-induced mesothelioma in a mouse model, by C. Robinson, S. Woo, A.K. Nowak, et al (Nutrition and Cancer, 2014).

The study

• Authors: C. Robinson, S. Woo, A.K. Nowak, R.A. Lake
• Journal: Nutrition and Cancer
• Published: 2014;66(3):383-7
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Epidemiological studies suggest that vitamin and mineral intake is associated with cancer incidence. A prevention strategy based on diet or dietary supplementation could have enormous benefit, both directly, by preventing disease, and indirectly by alleviating fear in millions of people worldwide who have been exposed to asbestos. We have previously shown that dietary supplementation with the antioxidants vitamins A, E, and selenium does not affect overall survival nor the time to progression of asbestos-induced mesothelioma in MexTAg mice. Here we have extended our analysis to vitamin D. We compared survival of asbestos-exposed MexTAg mice provided with diets that were deficient or supplemented with 4500 IU/kg vitamin D (cholecalciferol). Survival of supplemented mice was significantly shorter than mice given a standard AIN93 diet containing 1000 IU/kg cholecalciferol (median survival was 29 and 32.5 weeks respectively). However, mice deficient in vitamin D had the same rate of mesothelioma development as control mice. Neither the latency time from asbestos exposure to diagnosis nor disease progression after diagnosis were significantly different between mice on these diets. We conclude that vitamin D is unlikely to moderate the incidence of disease in asbestos-exposed populations or to ameliorate the pathology in patients with established mesothelioma.

In plain English

In this animal experiment, the authors tested whether dietary vitamin D changed the course of asbestos-induced mesothelioma in MexTAg mice, a transgenic strain that develops mesothelioma after asbestos exposure. Starting two weeks before exposure, mice ate one of three diets: a standard diet (1000 IU/kg vitamin D as cholecalciferol; 27 mice), a supplemented diet (4500 IU/kg; 27 mice), or a deficient diet with only trace vitamin D (26 mice). Each mouse was injected in the peritoneum with two 3 mg doses of crocidolite asbestos, one month apart. Median survival was 29 weeks for supplemented mice and 32.5 weeks for standard-diet mice. The authors reported this as significantly worse survival with supplementation (P = 0.0174). Deficient-diet mice (median 32 weeks) did not differ significantly from standard-diet mice (P = 0.31). Neither the time to diagnosis nor survival after diagnosis differed significantly between diets. Blood vitamin D levels followed the diets, but samples were pooled and not statistically tested. The authors concluded that vitamin D is unlikely to moderate disease incidence in asbestos-exposed populations.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Animal experiment in a transgenic mouse model of asbestos-induced mesothelioma, comparing three diets
• Who was studied: MexTAg 299h transgenic mice, matched for age and gender balance: 27 on the control diet, 27 on the vitamin D-supplemented diet and 26 on the vitamin D-deficient diet; research carried out at the University of Western Australia, Perth
• Exposure: Crocidolite asbestos (IUCC reference sample of Wittenoom Gorge crocidolite), injected into the peritoneum as 2 doses of 3 mg one month apart. Diets began 2 weeks before exposure: control 1000 IU/kg cholecalciferol, supplemented 4500 IU/kg, deficient with trace amounts only
• Main results:
  • Vitamin D supplementation was significantly detrimental to survival (P = 0.0174). Median survival was 32.5 weeks for the control diet, 29 weeks for the supplemented diet and 32 weeks for the deficient diet
  • Survival of mice on the vitamin D-deficient diet was not significantly different from control mice (P = 0.31)
  • Latency (time from disease induction to diagnosis) was not changed by any of the diets (P = 0.42)
  • Survival after diagnosis was not significantly affected by the diets (P = 0.068)
  • In pooled serum samples, vitamin D (25-OH form) in supplemented mice was 1.2-fold higher than in control mice at 8 weeks and 1.5-fold higher at 34 weeks. In deficient-diet mice it was fivefold lower than in control mice at both 8 and 34 weeks
  • Mice on low vitamin D intake were overrepresented among long-term survivors, but the survival difference from controls was not significant
• The authors' conclusion: The authors concluded that vitamin D is unlikely to moderate the incidence of disease in asbestos-exposed populations or to ameliorate the pathology in patients with established mesothelioma
• Limitations the authors state:
  • Serum had to be pooled from 6 mice per group because of the small volume available per mouse, so the serum vitamin D data were not statistically analyzed
  • The mice carry the SV40 large T antigen transgene, which interacts with the tumor suppressor genes Rb and p53. The authors argued that vitamin D does not directly interact with these pathways and hypothesized that the transgene would not interfere with the outcome

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Wittenoom, Western Australia

All asbestos mines

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Overall Survival, Median Survival, Latency, Asbestos Exposure, Disease Progression, Pathology.

Related studies

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• Effect of NSAIDS and COX-2 inhibitors on the incidence and severity of asbestos-induced malignant mesothelioma: evidence from an animal model and a human cohort — C. Robinson, H. Alfonso, et al. (2014)
• Estimated intake of vitamin D and its interaction with vitamin A on lung cancer risk among smokers — T.Y. Cheng, G.E. Goodman, et al. (2014)
• Antitumor-specific T-cell responses induced by oncolytic adenovirus ONCOS-102 (AdV5/3-D24-GM-CSF) in peritoneal mesothelioma mouse model — L. Kuryk, A.W. Møller, et al. (2018)
• Safety of Same-Day Vitamin B12 Supplementation in Patients Receiving Pemetrexed for the Treatment of Non-Small-Cell Lung Cancer or Pleural Mesothelioma: A Retrospective Analysis — Z. Schlei, W. Tan, et al. (2018)
• Dietary vitamin A and prevalence of bronchial metaplasia in asbestos-exposed workers — S.T. Mayne, C.A. Redlich, et al. (1998)

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