Multiple clinical studies have analyzed association of levels of vitamin A (retinol) with cancer risk. Levels of Vitamin A (retinol) were positively associated with risk of prostate cancer, as examined in large numbers of cancer patients. This indicates that use of excessive vitamin supplements to support health and well being may not necessarily add much value to us and could have a potential to cause harm.
Multivitamin supplement use is on the rise in the aging baby boomer generation for health benefits and supporting general well being. Most people believe that high dose vitamin intake is an anti-aging, immunity-boosting and disease prevention elixir, that even if not effective, can do no harm. With the widespread use of vitamins across global populations, there have been multiple observational retrospective clinical studies that have looked at associations of different vitamins with their cancer preventative role. In this blog, we specifically looked at the studies that have examined the association of levels of retinol (vitamin A) in the serum and risk of different cancers including prostate cancer.
Vitamin A (Retinol) and Cancer Risk
Below is a summary of some of these studies and their key findings:
- A pooled analysis of 15 different clinical studies published in the American Journal of Clinical Nutrition in 2015, looked at over 11,000 cases, to determine association of levels of vitamins and cancer risk. In this very large sample size, levels of retinol were positively associated with prostate cancer risk (Key TJ et al, Am J Clin Nutr., 2015).
- An observational analysis of over 29,000 samples from the alpha-tocopherol, beta-carotene cancer prevention study conducted by National Cancer Institute (NCI), National Institute of Health (NIH), USA, reported that at the 3 year follow-up, men with higher serum retinol (Vitamin-A) concentration had an elevated risk of prostate cancer (Mondul AM et al, Am J Epidemiol, 2011).
- A more recent analysis of the same NCI driven alpha-tocopherol, beta-carotene cancer prevention study of over 29,000 participants between 1985-1993 with a follow-up to 2012, confirmed the earlier findings of the association of higher serum retinol concentration with increased risk of prostate cancer. Higher serum retinol was not associated with overall cancer risk and observed to lower risk of liver and lung cancer, but across multiple studies there has been a positive correlation seen between serum Retinol (Vitamin A) levels and elevated risk of prostate cancer (Hada M et al, Am J Epidemiol, 2019).
These studies indicate that high intake of Vitamin A is associated with an increased risk of prostate cancer. What does this data mean for us? It indicates that excess of vitamin supplements to support health and well being may not necessarily add much value to us and could have a potential for causing harm. What is better for us is getting our source of vitamins and minerals through natural sources and a healthy nutritious diet.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer. Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.