Over the past 150,000 years, skin color has evolved depending on the migration patterns of our ancestors. Skin pigmentation changed to ensure our ability to adapt to new environmental and geographical regions. As civilizations and technology evolved, making it far easier to move from one place to another, we migrated out toward the poles, dispersing ourselves from the equatorial latitudes of tropical Africa, South America and Asia. Today, recognizing how well your skin color fits with your chosen environment is especially important to your health.
Often we choose to live in places our skin is not well suited for – who doesn’t want to live where it is warm and sunny all the time? But, this can create potential health risks if we aren’t careful. In our ancestors, melanin production (the body’s natural sun protection) was directly proportional to exposure from the sun’s powerful ultra violet rays (UVR). Our bodies actually need UVR exposure in order for our skin to produce Vitamin D, which is a vital nutrient for bone development and other critical body and cell functions. But UVR is also highly destructive to Folic Acid, a B vitamin that is essential for DNA production and maintenance. So, we’re locked into a Catch 22 between protecting our skin and DNA and also ensuring we get enough UVR to support our body’s need for Vitamin D. What is a person to do?
Fortunately for our ancestors, nature had an answer. As people migrated from areas where UVR exposure from sun is the strongest, the skin began to lighten (produce less melanin), to permit the right balance between Vitamin D synthesis and DNA protection.
Because of the mutually exclusive needs to produce Vitamin D and protect DNA, there is a very clear cartographic relationship between skin color and latitude. The farther away from the equator your ancestors lived, the lighter their skin became. As a side note of interest, though skin color has long been used to identify a person’s ethnic background, skin color is not genetically linked to any race – it simply indicates where your ancestors live in relation to the equator (where the highest levels of UVR exist).
There is a lot of public awareness about using sunscreen, but much less is said about how sunscreen can prevent Vitamin D production and lead to serious health problems. Understanding this relationship between skin color and vitamin D production can help you make informed decisions about your family’s skincare and eating routines to actively maintain health. For example, a fair-skinned child living in Africa might suffer DNA damage from over-exposure to UVRs and, therefore, extra attention should be given to sun protection. Conversely, a dark-skinned child living in Finland might need substantial quantities of vitamin D in their diet to prevent calcium deficiencies and maintain the many other essential functions that depend on an ample supply of vitamin D.
Getting vitamin D from dietary sources can be a challenge as the best nutritive sources are certain types of fish and fortified dairy products. Consequently, there is a global epidemic of Vitamin D deficiency. Some are at greater risk than others. The darker your child’s skin, the more sun exposure and/or supplementation is needed to produce sufficient quantities of Vitamin D. Knowledge about skin color and the health factors related to it allows us to take the necessary measures to ensure proper health for all.
Get Dr. Greene's Wellness Recommendations
Sign up now for a delightful weekly email with insights for the whole family.