July 23, 2024

The World's Local Health

New Evidence around Vitamins and Cancer Prevention

4 min read
New Evidence around Vitamins and Cancer Prevention

As doctors, many have asked us, “What vitamins can I take to prevent cancer?” This is a difficult question and we often hesitate to claim that taking vitamins is a miracle cure to prevent this dreaded illness. However, there is increasing evidence that consumption of vitamins, especially certain important individual vitamins that are deficient, may play a role in the prevention of cancer. As physicians, we tell our patients to do certain things to prevent cancer, including healthy eating, safe drinking, regular exercise, and, of course, recommended tests such as mammography, colonoscopy, and prostate screening. 

The Power of Vitamin D

One of the latest pieces of information that has caught our attention is the suggestion that vitamin D may help protect against the risk of colon cancer, especially in people under the age of 50. 

New evidence suggests that vitamin D may be a cheap and effective way to reduce the risk of precursors such as early-onset colon cancer (“CRC”) and colorectal polyps. The study, conducted by Harvard physicians and researchers, examined 111 new cases of early-onset CRC and found that the risk to those who took 400 IU / day on a  diet or supplement was significantly reduced. 

According to one of the study’s authors, Kimmie Ng, M.D., M.P.H., of the Dana-Farber Cancer Institute, “We found that total vitamin D intake of 300 IU per day or more – roughly equivalent to three 8 oz. glasses of milk – was associated with an approximately 50% lower risk of developing young-onset colorectal cancer.” This study began in 1989, and used data from the Nurse Health Survey II (“NHS II”), a prospective cohort analysis of nurses, aged 25-42. The study was based on self-reported data about diet and lifestyle factors given every two years. There are limits to this methodology- the self-reporting nature of the data confirms that the association between vitamin D and CRC has been reported in other studies using randomized clinical management and laboratory science.

The American Cancer Society

To further explain the link, the American Cancer Society has published data on its website showing that people with vitamin D deficiency have a 31% increased risk of developing CRC, when followed over 5 years. In addition, the same data shows that excess vitamin D levels did not reduce risk levels. Therefore, there is no benefit to overdoing it with an excessive amount of vitamin D supplements. Nature, a publication, reviewed seven randomized clinically controlled studies, including 957 CRC cases, and found that vitamin D supplementation reduced adverse outcomes of CRC by 30%. Meta-analyses of these RCT studies have found significant benefits in supplementing the cases of CRC survival. The results of these studies are meaningful when we consider how vitamin D works. Calcitriol, 1α, 25-dihydroxyvitamin D3 (1,25 (OH) 2D3) is the most active form of vitamin D, which binds to the vitamin D receptor and regulates the expression of many genes involved in growth, differentiation and survival of cancer cells.  

The Centers for Disease Control and Prevention

According to the Centers for Disease Control and Prevention (CDC), colorectal cancer is the third most common cancer in both men and women and the third most common cause of cancer-related deaths in the United States. Globally, CRC causes 1.8 million cases and approximately 860,000 deaths worldwide each year. The National Cancer Center reports that the incidence of early-onset CRC has nearly doubled since the 1990s. If vitamin D supplementation can improve CRC-related diagnoses and outcomes, it has significant implications for the health of the population. 

Supplements and cancer prevention: What you need to knowMD Anderson  Cancer Center

Is Regular Diet Enough?

We repeatedly share that it is difficult to get enough vitamin D from diet alone. This view is endorsed by Elena A. Ivanina, director of neurogastroenterology and motility at Lenox Hill Hospital in New York. The average intake of vitamin D through diet is only 204 international units (IU) for men and 168 IU for women – significantly below the recommended daily allowance. Diet aside, we know that many people do not have sufficient access to sunlight to prevent deficiency, and fear of exposure to UV light, the spread of sunscreens impedes the absorption of sunlight.

The Takeaway

So what is the takeaway? How Much Vitamin D Do I Need to Take as a Supplement? It turns out that the answer is not the same for everyone. We are all individuals with different vitamin needs. Things like sun exposure, ethnicity, and other conditions affect the amount each person needs to take. High quality daily vitamins with sufficient vitamin D can bring significant benefits to CRC, especially in young individuals under the age of 50. 

However, while over-the-counter multivitamin options may contain vitamin D, they may not be sufficient for a particular individual’s profile. Therefore, it is important to perform a medically-backed assessment and learn vitamin D dosages that are appropriate for your individual nutrition, fitness, health, and lifestyle profile. 

It is always important to discuss your vitamin needs with your doctor and work together to determine if the product you are taking is the right solution for your overall health. Personalized vitamins are often a good start to getting basic essential nutrients that are customized to your specific needs. We have long known that vitamin D has many benefits associated with immunity, bone health, and many others. There is increasing evidence that it may help CRC, the leading cause of cancer death.