Many Americans are unaware that they have low Vitamin D levels, and a number of health problems have been linked to that situation. In addition, many health benefits have been reported for those that maintain adequate levels of the vitamin. A new study by researchers in the United Kingdom has found that maintaining an adequate Vitamin D level increases survival among intestinal cancer patients. The study was published online on July 7 in the Journal of Clinical Oncology by researchers at the University of Edinburgh (Edinburgh, Scotland) and Trinity College Dublin (Dublin, Ireland).
The researchers conducted a study to determine whether the plasma level of Vitamin D after a diagnosis of colorectal cancer influences survival outcome. The study group comprised 1,598 patients with stage I to III colorectal cancer. The patients were followed in regard to an association between plasma Vitamin D levels and stage-specific survival, meaning that survival among various stages of the disease was taken into account. The subjects were also tested for interaction between their Vitamin D level and variation at the Vitamin D receptor (VDR) gene location. Blood was drawn postoperatively to measure plasma Vitamin D levels. Genetic analysis was also done to detect genetic variations. The data was detected to statistical analysis to assess survival.
The investigators discovered strong associations between plasma Vitamin D level and both colorectal cancer-specific mortality and all-cause mortality (death from any cause). They also found that genetic variants in the Vitamin D receptor gene affected mortality. They concluded that among patients with stage I to III colorectal cancer, postoperative plasma Vitamin D is associated with clinically significant differences in survival outcome; higher levels were associated with better outcome. They observed interactions between the Vitamin D level and variations in the Vitamin D receptor gene, which suggested a causal relationship between Vitamin D and survival. They recommended that further studies regarding the influence of Vitamin D supplementation on colorectal cancer survival should be conducted.
Take home message:
This study reports that maintaining an adequate Vitamin D level increases survival among colorectal cancer patients. Due to its Sunbelt location, natural sunlight is plentiful most days of the year. However, excessive sun exposure ages the skin and increases the risk of skin cancer. Vitamin D supplements are inexpensive and readily available. Also, some food products such as milk and orange juice are fortified with Vitamin D. The current recommendations by the Institute of Medicine (IOM) are based on age:
- Age 1-70 years: 600 IU daily
- Age 71 years and older: 800 IU daily
- Pregnant and lactating women: 600 IU daily