Critique of Vitamin D and Cancer

Introduction

Recently the International Agency for Research on Cancer (IARC) conducted research and released a report on it. The report called “Vitamin D and Cancer” focuses on the current knowledge and evidence of the relationship between cancer risk and vitamin D relation to it. Although the research evaluates and presents evidence on the important role of vitamin D and UVB in eliminating risks of cancer, the report, however, omitted or discounted the useful evidence that supported vitamin D’s efficacy. Also, the report ignored or dismissed the ecological studies with an assumption that factors that were to be confided could influence the findings (Grant, 2009). IARC’s report suggested Vitamin D’s preventive role in colorectal breast cancer.

There are more than 1360 references listed in this particular report. Many of these references support the beneficial task of vitamin D and UVB in eliminating the risks of various types of cancers. Besides listing these many references with mostly positive findings, the report overemphasizes a few negative findings at the conclusion. The first and the fifth conclusions are the only conclusions that have been seen to be consistent with included data in the report (Grant, 2009). Based on the evidence that is available, a few of the other conclusions are seen to be unfair or wrongfully dismissive.

The seven conclusions suggest that, although the epidemiological observation evidence gave support to vitamin D’s role in eliminating colorectal cancer risks, the evidence is not causal. Also, the RCT, until now, has not provided support to observational evidence. Despite the fact that breast cancers are similar in terms of evidence, the pieces of evidence are weaker. Concerning the role of Calcium and vitamin D in the prevention of cancer, these conclusions are also weak for a detailed review of scientific evidence.

Vitamin D and Cancer

Critique of chapter 3

The International Agency for Research on Cancer analysis of the relationship between the incidence of melanoma and the artificial UV sources does not give an attempt to elaborate on the skin types. The report suggests that the usage of the artificial UV sources results in skin cancer epidemic in Nordic countries and the Netherlands. However, this suggestion could not be correct, since an increase in the exposure to sunrays at the time of travel by the people who live in the northern part of Europe accelerates melanoma incidence (Grant, 2009). The people who stay along the high latitudes of Europe have dark skin pigmentation and they are likely to keep lower risks of melanoma even with an increase of exposure to the solar rays. The authors of this report assume an elevated risk of melanoma which is a significant reason for avoiding the artificial and the solar UV irradiance. Many of the artificial UV sources give about 3-5% of the UV which is about the same level as that of solar UV.

Critique of Chapter 5

The 5th chapter talks about the toxic effects related to a long term intake of Vitamin D. The newest review of literature found that there were no reports on toxicity that was lesser than 20000 IU/day of vitamin D (“Cancer: Vitamin D boosts cancer treatment”, 2014).

The appendix for chapter 5 of the IARC report gives an RCT finding on the continued effects of supplements that are thought to be reducing the cancer risks. I tend to agree with the RCT’s results suggesting that vitamin supplement like vitamin A, C, E and beta-carotene do not meet the expectations, and I have a strong feeling that vitamin D is not appropriate to be compared with them. Unlike other vitamins, the metabolic form of vitamin D is an active hormone and is produced by the body naturally (Grant, 2009).

I think that history of eradication of the disease by means of the identification of vitamins that were missing in diet or UVB provided a good guide in what would have been accomplished with an increase of vitamin D.

Critique of Chapter 8

The 8th chapter of the IARC report superficially discusses what is known concerning the roles of the vitamin D in the elimination of the risks of cancer. The 1,25 (OH)D anti-neoplastic properties are certainly of an importance while eliminating the incidences of cancer. However, the chapter does not give an explanation of why people that have been diagnosed with cancer during summer live four year longer than those people who have been diagnosed with cancer during the spring or winter. Neither do they give an explanation of why women taking vitamin D at their postmenopausal period had a 40 percent decline of all forms of cancer between the end of the first and fifth year of RCT. The reason would be assumed to the role of vitamin D in the reduction of metastasis or angiogenesis. This vitamin has an effect of increasing calcium absorption that has proven to be an important factor of risk reduction for several types of cancers.

Critique of Chapter 11

The 11th chapter suggested that the one and only study that showed a strong interrelationship between vitamin D and cancer was that of pancreatic cancer. This was a study that had involved more than 110000 participants. There was also a great reduction of the risk in three of the five quintiles of vitamin D out of the diet. Many of such kinds of observational studies have a problem in that the diet gives very small quantities of vitamin D for them to have a noticeable effect on the risks of cancer.

Critique of Chapter 12

The IARC report agrees that vitamin D has a preventive role in cancer. However, the same report discounted a similar evidence in the elimination of risks associated with the breast cancer (Grant, 2009). This is inexplicable, as the breast cancer is at the top of the cancer mortality rates among the population, similarly to the rates of colorectal cancer.

Critique of Chapter 15

IARC discusses the skin solar elastosis, and it gives the correct conclusion suggesting that solar elastosis has not been the best market on the lifetime radiation of the solar UVB and the production of vitamin D. One reason has, however, been overlooked in this particular discussion, and that is the role of smoking in elastosis. Same as the solar UV, smoking also produces skin elastosis. There is obvious connection between smoking and melanoma risks

A study of women who have been diagnosed with breast cancer showed that in the 12 year follow up time, women that had serum 25(OH)D of a greater level than 30ng/ml when the diagnosis was being conducted, had 17% mortality rate (Ma, 2010). Those women whose levels were lesser than 20ng/ml, were found to be having a 33% mortality rate.

Conclusion

Vitamin D has health benefits that help in the treatment of cancer. The IARC report calls the RCT’s settlement of the issue on supplementation of vitamin D. Though the RCT would have been beneficial, the development of an effective and a sound policy of public health does not depend on them. Therefore, the report conducted by the IARC should not create a basis for decisions by the public health policy.