Scientists discover three genes related to skin color and the risks of severe vitamin D deficiency.

A new study suggests that genes related to skin color may be the strongest indicator of whether a person is deficient in vitamin D or not.

The researchers found that African-American participants with a specific mutation had vitamin D levels up to three times lower than what is considered the normal range for a healthy person.

Scientists have found that having low levels of vitamin D is linked to several cancers, including breast, colon, rectum and prostate, in addition to COVID-19.

The team, from City of Hope, an independent biomedical research and treatment center based in Duarte, California, says the findings suggest that in the future, doctors could better prescribe the right dose of vitamin D supplements and help to decrease the risk of these diseases.

“We should not shy away from this new study on skin color genetics and its effects on vitamin D deficiency, because being‘ colorblind ’is what has led to widespread health disparities that now as a society we are trying to address it, ”he said. Dr. Rick Kittles, director of the Health Equity Division of the Beckman Research Institute of the City of Hope.

Vitamin D is sometimes called “vitamin of the sun” because the skin creates it naturally when exposed to sunlight.

It is found in foods such as milk, cheese, egg yolks, tuna and salmon, although often in low amounts, which is why supplements are sometimes needed.

Epidemiological research has suggested that incidence and mortality rates for certain types of cancer are lower among people living in southern latitudes, with high levels of exposure to sunlight, compared to those living in latitudes. north.

In addition, previous studies have found that having “adequate” levels of vitamin D reduces the risk of serious complications and death from COVID-19.

In addition, race is one of the biggest predictors of low vitamin D levels.

“Skin color is of great social and biological importance: social because of race and racism and biological, as more than 70% of African Americans are deficient in vitamin D, leading to an increased risk of cancer and disease cardiovascular, ”Kittles added.

For the study, published in the journal PLOS Genetics, the team examined data from 1,076 people who identified as African American.

Researchers collected blood samples, which they used to analyze DNA and vitamin D levels.

They also measured the skin covering the upper inner arm area using a digital reflectometer.

They examined three genes with strong links to skin color: SLC24A5, SLC45A2 and OCA2

All three provide instructions for making a protein found in melanocytes, which are specialized cells that produce melanin, the pigment that determines skin color.

Black participants with a genetic variant of the gene called SLC24A5 were more likely to have vitamin D levels of 12 nanograms per milliliter (ng / mL) or less.

Normal levels vary between 20 and 40 ng / mL for a healthy person.

The team hopes to use their findings to create an assessment of the risk score that can be used one day in doctors ’offices.

For example, in the future, a doctor might evaluate a person’s skin tone and lifestyle and use the tool to prescribe the right dose of vitamin D supplements.

“This study is an example of the interaction of race and skin color with health and how if we ignore things like a person’s skin color, we may be ignoring possible medical issues, thus contributing to disparities. welfare, ”Kittles said.

“Our study provides new insights into an easily modifiable factor such as vitamin D supplementation and inherited genetic factors that affect vitamin D deficiency in African Americans.

“With more research, in the future doctors could offer color patients a cost-effective way to reduce their risk of vitamin deficiency, which could ultimately help protect against certain cancers.”