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High blood levels of vitamin D and magnesium lower your risk of dying of cancer

High blood levels of vitamin D and magnesium lower your risk of dying of cancerThe interplay between vitamin D, magnesium, and calcium is vital for bone health and a number of other things, including cancer prevention. According to a new study that is published in American Journal of Clinical Nutrition, high blood levels of vitamin D and magnesium may lower colon cancer patients’ risk of dying of their disease. However, the current recommendations for vitamin D are not enough to reach optimal blood levels of the nutrient. Moreover, it is of vital importance that magnesium is properly balanced with calcium.

Colorectal cancer is one of the leading cancer forms in Denmark. The health authorities recommend a screening program where middle-aged and older citizens are screened every other year for possible signs of colorectal cancer. If the disease is discovered in its early stage the chances of treating it are a lot better. According to the new study, it is also important to look at a person’s nutritional status because lack of certain nutrients increases the risk of contracting the disease and dying of it.

  • Every year, 5,000 Danes are diagnosed with colorectal cancer
  • Most of them are older than 50 years of age and the risk of dying of the disease increases the older you are

More focus on vitamin D and magnesium helps prevent cancer-related deaths

Vitamin D, magnesium, and calcium have a host of interactions in the body that are vital for cellular health and our own health. A group of scientists wanted to take a closer look at whether the interplay between vitamin D, magnesium, and calcium affects colorectal cancer patients’ risk of dying of their disease. Their study included 1,169 patients, all of whom were recruited from a large population study and had recently been diagnosed with colorectal cancer in the stages 1-3. The researchers measured the participants’ vitamin D status. Also, their intake of calcium and magnesium was calculated by looking at their diet and any use of supplements. Interactions between vitamin D, calcium, and magnesium were assessed by means of different methods.
It turned out that low blood levels of vitamin D were linked to an increased risk of dying of colorectal cancer, and the lower the magnesium intake, the higher the risk of dying of the disease. The scientists did not find any relation between calcium intake and various interactions related to colorectal cancer mortality
The lowest mortality risk was observed among the patients that had high blood levels of vitamin D (more than 50 nmol/L) and consumed the most magnesium from dietary sources and supplements. They ended up concluding that sufficient vitamin D in the blood combined with high magnesium intake from dietary sources or supplements lowers the risk of dying of colorectal cancer. The study is published in American Journal of Clinical Nutrition.
Also, the scientists suggest taking a closer look at underlying mechanisms concerning interactions between vitamin D, magnesium, and calcium, and they call for more studies of diet and lifestyle to corroborate their findings. In any case, it is relevant to look at the known interactions between vitamin D, magnesium, and calcium that are of importance for preventing several other cancer forms, osteoporosis, and various chronic diseases.

Ageing makes it increasingly difficult for people to synthesize vitamin D from the sun in the summertime

Vitamin D is activated by magnesium

When humans synthesize vitamin D from the sun, they produce the form of vitamin D called cholecalciferol that is also found in many supplements. This form of the nutrient is not biologically active and needs to be converted by magnesium-containing enzymes, first in the liver and then in the kidneys. This means that lacking magnesium reduces the activity of vitamin D and many of the processes, in which the vitamin takes place. Vitamin D is important for the body’s calcium uptake, the immune defense, blood sugar management, hormone balance, and cancer prevention through regulation of a host of different genes.

How to measure vitamin D levels in the blood

Vitamin D in the blood is measured as 25-hydroxyvitamin D. The official threshold value is 50 nmol/L but leading scientists find this to be inadequate and suggest as much as 75-100 nmol/L for optimal disease prevention.

Magnesium’s interactions with calcium

The interaction between calcium and magnesium is fundamental to all living cells. Our bones and teeth store around 99 percent of the body’s calcium, whereas cells in our soft tissues such as our internal organs and muscle and nerve tissue hardly contain any calcium. Magnesium, which serves as a “door bolt” in the calcium channel of the cell membranes, makes sure that only very little calcium enters these cells.
If we lack magnesium, the calcium channels are left open with the risk of calcium streaming into the cells. This stresses the cells and increases the risk of poor energy utilization plus chronic inflammation, which is a common thread in most chronic diseases, including cancer.

The relation between calcium and magnesium

Health authorities and scientists have not reached common ground with regard to our actual need for calcium and magnesium and the optimal ratio between these two nutrients. In Denmark, the reference intake (RI) level for calcium is 800 mg and 375 mg for magnesium, which gives a 2:1 ratio. In places like Japan, the ratio is closer to 1:1, which is because the Japanese do not eat dairy products and only get around 400-500 mg of calcium daily. On the other hand, they get much more magnesium from vegetable sources.


Wesselink E et al. Vitamin D, magnesium, calcium, and their interaction in relation to colorectal cancer recurrence and all-cause mortality. Am J Clin Nutr. 2020 mar 19

Qi Dai el al. Abstract CT093: Bimodal relationship between magnesium supplementation and vitamin D status and metabolism: Results from randomized trial. Cancer Research July 2018

Andrea Rosanoff et al. Essential Nutrient Interactions: Does Low or Suboptimal Magnesium Interact with Vitamin D and/or Calcium Status. Advances in Nutrition 2016

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