Vitamin D makes melanoma less aggressive

Melanoma can be very dangerous if it is not treated in time, but a study from the University of Leeds in England shows that vitamin D affects melanoma cells and makes them less aggressive. According to the scientists behind the study, this revelation may lead to new therapies. It is a problem, however, that health authorities warn people against sun exposure without informing about alternative ways to optimize vitamin D levels. The sun during the summer period is our main source of vitamin D, so we just have to make sure not to get burned. At our latitudes, it is a good idea to take a vitamin D supplement during the winter period. According to other studies, the nutrient prevents cancer by way of several different mechanisms.

Melanoma, also called malignant melanoma, is a cancer that normally begins in birthmarks (in rare cases, it may start in other places). It is primarily caused by excessive sun exposure, including frequent use of tanning beds. Especially severe childhood or teenage sunburns tend to increase the risk. Other risk factors include having light skin that does not tan easily, having blondish or reddish hair, or blue eyes. Because malignant melanoma is so dangerous, early diagnosis and treatment are essential for survival. It is only natural for the number of birthmarks to increase with age, and most of them are completely harmless. Still, it is important to keep an eye on them and notice any changes in their color, size, or edges. Also, notice if there is any itching, liquification, or bleeding from any of the birthmarks. Malignant melanoma is normally diagnosed with help from a tissue sample taken from a suspicious-looking birthmark. Treatment typically involves surgical removal of a large skin area surrounding the diseased birthmark, possibly followed by radiation, chemotherapy, or immunotherapy.

How vitamin D and VDR protect against melanoma

Earlier research shows that low blood levels of vitamin D are linked to a poorer diagnosis for patients with malignant melanoma, but the scientists have not fully understood the mechanisms behind vitamin D deficiency and the development of the disease. For that reason, Professor Newton-Bishop from the University of Leeds and her team of scientists decided to look closer at the processes that are controlled by vitamin D inside melanoma cells. They also wanted to see what happened if melanoma cells lacked the vitamin D receptors (VDR) that bind vitamin D.
The researchers studied the activity of the VDR-coding gene in 703 human melanoma tumors and 353 human metastases that had spread from their original site. The VDR activity was compared to the thickness of the melanomas in the different patients and to the rate at which they increased in size.
The scientists also wanted to see if the number of VDRs in melanoma cells was linked to the genetic changes that occur when cancer cells become more aggressive. In order to do this, they conducted studies on mice to see whether the number of VDRs affected the cancer cells’ ability to spread. They found that tumors with few VDRs had increased gene activity and signaling (Wnt/beta-catenin) that is associated with the growth and spreading of cancer.
When the scientists increased the number of VDRs in melanoma cells from mice, the activity in the same signaling pathways and the growth of melanoma cells decreased. The scientists also saw that the cancer had difficulty with spreading to the lungs of the mice.
After years of research, the scientists now understand how vitamin D and VDR affect the genes and signaling pathways that can help make the melanoma cells less aggressive and give the immune defense a boost so it can fight the cancer cells.
Although vitamin D as monotherapy is not able to treat cancer, the scientists say that taking a vitamin D supplement has the potential to improve the results of conventional therapy. Therefore, they recommend that patients with melanoma have their vitamin D levels measured. The new study is published in Cancer Research.
For the record, vitamin D protects against several common cancers, so anyone who lives at northern latitudes or for some reason does not get enough vitamin D all year round should ideally have their vitamin D levels measured.

How do we get enough vitamin D?

The sun during the summer period is our most important source of vitamin D. However, the amount of vitamin D stored in our liver is often limited, and we only get a small amount of the nutrient from the food we eat.
In Denmark, a typical vitamin pill contains as little as five micrograms of vitamin D, which is also the reference intake (RI) levels for adults under the age of 70 years. In England, it is 10 micrograms, and it is 15 in the United States. Many researchers claim that we need even higher quantities in order to cover our needs.
You can also find high-dosed supplements on the market with as much as 20-80 micrograms of vitamin D. A person’s actual need hinges on a variety of factors such as sun exposure, age, skin type, BMI, the use of cholesterol-lowering medication, and chronic diseases like diabetes.
Because vitamin D is a lipid-soluble nutrient, you get the best bioavailability by taking it in capsules, where the vitamin is mixed in oil.

Optimal blood values require supplements

Vitamin D in the blood is measured as 25-hydroxyvitamin D3. In Denmark, the lower threshold for vitamin D in the blood is 50 ng/ml. Professor Garland and several other leading experts say that you need as much as 60-100 ng/ml to obtain optimal disease prevention. Blood levels of vitamin D higher than 125 ng/ml may be associated with symptoms such as nausea, constipation, weight loss, heart rhythm disturbances, and kidney damage.
It is not possible to synthesize too much vitamin D from sunlight exposure, and vitamin D supplements should be adjusted to individual needs.

References

Sathya Muralidhar et al. Vitamin D-VDR signaling inhibits Wnt/beta-catenin-mediated melanoma progression and promotes anti-tumor immunity. Cancer Research 2019

Cancer Research UK. Vitamin D dials down the aggression in melanoma cells. ScienceDaily. 2019

Varun Samji et al. Role of vitamin D supplementation for primary prevention of cancer: Meta-analysis of randomized trials. Journal of Clinical Oncology, 2019

Michigan State University. Vitamin D could help cancer patients live longer. ScienceDaily. June 2019

Melina Arnold et al. Progress in cancer survival, mortality, and incidence in seven high-income countries 1995-2014. (ICBP SURMARK-2): a population-based study. The Lancet. September 2019

University of California – San Diego. Greater Levels of vitamin D associated with decreasing risk of breast cancer. June 15, 2018

Hutch News. High blood levels of vitamin D linked to reduced estrogen – and potentially lower breast cancer risk. 2016

Sharon L. McDonnel, Cedric F Garland et al: Serum 25-Hydroxyvitamin D Concentrations ≥40 ng/ml Are Associated with >65% Lower Cancer Risk: Pooled Analysis of Randomized Trial and Prospective Cohort Study PLoS One: 2016

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