Vitamin D has anti-cancer effects, and it is more obvious in old age!

A study recently published in BMC Public Health found that there is an inverse relationship between ultraviolet (UVB) exposure and the crude incidence of colon cancer , and this relationship is stronger in the elderly
.

https://doi.
org/10.
1186/s12889-021-11089-w

Colorectal cancer (CRC) is the third most common cancer in the world, with more than 4 million patients
.
Nearly 2 million new cases of colorectal cancer were reported globally in 2018

Some of the factors currently known to be associated with an increased risk of CRC include obesity, a sedentary life>
.
In addition, insufficient vitamin D status assessed by serum 25- hydroxyvitamin D (25(OH)D) concentration has also been identified as a potential risk factor in the pathogenesis of CRC

Vitamin D has many effects on cells
.
In cancer research, the "DINAMIT (separation, initiation, natural selection, overgrowth, metastasis, involution, and transition)" process of vitamin D describes a series of events that occur at the cellular level when vitamin D is low

DINOMIT process during vitamin D deficiency

Vitamin D for Cancer Prevention: Global Perspective.
https://doi.
org/10.
1016/j.
annepidem.
2009.
03.
021

People generally do not have rich vitamin D content in their diet, and they mainly rely on the production of endogenous vitamin D after exposure to ultraviolet light (UVB)
.
Affected by light, vitamin D deficiency is seasonal and regional

In this latest study, researchers analyzed the global differences in CRC and found that although the incidence of cancer in young people in low UVB countries is almost the same as that in young people in high UVB countries, when observing people over 45 years old, the incidence of cancer is low.
The cancer incidence rate of people in UVB countries is much higher than that of people in high UVB countries
.

The study used Cancer Today to collect a global database, and included 186 countries’ morbidity, mortality, and epidemiological data of various cancers by age stratification to analyze global UVA light levels in 2017 and 0-75 in 2018.
The relationship between the incidence of colorectal cancer in the age-old enrolled population, and comprehensively considered skin pigment, urbanization, smoking rate, per capita GDP and other factors for regression variable analysis
.

Researchers have found that UVB in different age groups is negatively correlated with the incidence of CRC, which means that people with low UVB exposure are more likely to develop colorectal cancer
.

This reminds us that if you live in a country with more UVB sunlight, you may have an advantage when it comes to cancer risk
.
For people farther from the equator, there is less chance of exposure to ultraviolet light, while people living in countries close to the equator are bathed in ultraviolet light most of the year

Global UVB distribution
.
The darker the color, the higher the UVB level

Estimated crude incidence of CRC between 60 and 74 years of age estimated by UVB in 2018

The researchers also discussed the relationship between global latitude, UVB levels and the incidence of CRC
.
According to reports, UVB levels decrease with increasing latitude, and the higher the latitude, the higher the probability of colorectal cancer

Does this mean that vitamin D is not needed before old age? Not so
.
The carcinogenic effects of low vitamin D take a long time to develop

If vitamin D cannot be supplemented by sun exposure for various reasons, additional measures need to be taken, including eating foods rich in vitamin D (such as fatty fish and dairy products) or taking vitamin D supplements
.
Studies have shown that maintaining vitamin D levels at 40ng/ml may be the lowest effective target for cancer prevention
.

Serum 25-Hydroxyvitamin D Concentrations ≥40 ng/ml Are Associated with >65% Lower Cancer Risk: Pooled Analysis of Randomized Trial and Prospective Cohort Study.
https://doi.
org/10.
1371/journal.
pone.
0152441

Original source:

Could age increase the strength of inverse association between ultraviolet B exposure and colorectal cancer?https://doi.
org/10.
1186/s12889-021-11089-w