A pigment found in the cells of our body, melanin gives our skin, hair and eyes their specific color. People with fair or light skin have less melanin than those with a darker, more tanned skin color. Melanin is also responsible for the natural color of our hair and eyes. The partial or total lack of melanin resulting in features such as white hair, light blue eyes and an extremely pale skin color is called albinism. While it is not a debilitating condition, albinism leaves the body unprotected from UV radiation which may lead to serious health problems over time.
For this reason people with darker complexions indicating higher melanin concentrations in the skin are generally considered healthier than fair-skinned people because they are more protected from UV rays and thus have a lower risk for sunburns and skin cancer in particular. However, it has been shown that while more melanin does offer a higher degree of protection against radiation from sunlight, it also reduces our production of vitamin D, a nutrient with significant immune system-boosting and bone-strengthening properties and a wide range of other health benefits.
Melanin is a pigment of the skin, eyes and hair resulting from the synthesis of an amino acid called tyrosine. The melanin in our skin comes from special cells located deep in the epidermis, known as melanocytes. When the body is deficient in melanin, albinism occurs. Plants, animals and people can develop this condition. Although it does not pose serious health problems from the beginning, albinism lacks certain protective mechanisms. For instance, the melanin in our eyes colors the iris in order to make it more opaque and protect against UV radiation and excess light. Albinism means more exposure to light radiations, photosensitivity and retina and optic nerve damage.
Also, people suffering from a melanin deficit will also experience poor vision. Brown and black-eyed people are generally thought to have a sharper vision than blue or green-eyed people. Just as interesting is the fact that, over time, our iris slowly discolors as well. Maybe you have noticed how your parents or grandparents’ eye color has gone from light brown to light blue. Yes, it’s possible. This indicates not only lower melanin levels, but also a poor diet, lacking vitamin A, beta-carotene, zeaxanthin, lutein, all the nutrients required for a healthy vision (see all essential vitamins and minerals here).
The same thing happens with hair. As we grow older, less melanin is produced at the level of the hair root, causing new hairs to grow white or gray. This process is triggered by the death of the melanocytes (melanin-producing cells) at the base of our hair follicles and is one of the first signs of aging. High levels of melanin help preserve one’s natural hair (and eye) pigmentation longer.
Melanin boasts other incredible health benefits as well. For example, the melanin in our skin acts like a barrier against radiation coming from the sun. It is so efficient that it successfully repels 99.9% of radiation. When there is a total or even partial deficit of the pigment, the skin is more susceptible to developing sunburns and more serious skin damage that can allow the development of skin cancer.
For example, people with darker skin tones can generally tolerate more hours of sun exposure than fair-skinned people. If red-haired, fair-skinned, green-eyed individuals were to expose themselves to the sun, especially without having prior applied sun lotion, their skin would be less tolerant of the heat and radiation and exhibit mild to severe skin damage symptoms, including redness, sunburns or blisters.
Sun (over)exposure and poor melanin pigmentation have been linked to higher risks of skin cancer. If you are light-skinned, remember to always use sunscreen. The lighter the skin, the higher the UV protection factor it requires. The best sunscreen lotions are broad-spectrum ones, meaning they offer protection against both UVB and UVA. Some studies suggest that UVA are responsible for malignant melanoma, a common form of skin cancer. However, sun lotion is just as important if you have a darker skin too because radiation can still pass through and produce serious damage to the skin.
Need to read: some pharmaceutical companies will try to take advantage of people by promoting incredible melanin supplements. These are not reliable because the pigment is produced by cells in our skin, which we cannot simply bottle and sell. However, you can slightly discolor your skin naturally and give it a slight orange tan by consuming more beta-carotene-rich foods such as carrots, sweet potatoes or pumpkins. Eating a high amount of foods rich in lycopene can lead to a similar effect. The conditions are known as carotenosis (or carotenodermia) and lycopenemia.
Drinking plenty of water, eating a lot of fruits and vegetables and taking your vitamins is important for an overall healthy and beautiful skin. Also, remember that antioxidants such as vitamins C, A and E can help prevent skin damage due to free radical exposure.
Update 2017. Current tests set in place for measuring vitamin D levels in the body look for a certain protein that binds to the vitamin and a prehormone called 25-hydroxyvitamin D that is converted into an active form of vitamin D. African American people have often been found with low levels of this protein and prehormone and thus considered to be deficient in vitamin D and prescribed supplements. However, emerging research reveals genetical differences between dark and white skin people.
More exactly, African Americans and dark skin people in general have been found to naturally have less of these vitamin D binding proteins and prehormone because their ancestors used to live in areas were there was plentiful sunshine year round and thus did not need to store the vitamin (this is also the reason why they have more melanin and a darker skin, to have enough protection against sun radiation too).
Light skin people, who were living at higher latitudes, did not enjoy as much sunshine all year round, so their body evolved to store vitamin D for when there wasn’t enough sunshine, like in winter months. This is also the reason why they needed less protection from sunlight radiation (so had less melanin in their skin and, consequently, a lighter skin color), but also the reason why they have more vitamin D binding proteins (for storage purposes).
According to a more recent 2013 study from the New England Journal of Medicine (Vitamin D–Binding Protein and Vitamin D Status of Black Americans and White Americans), the reason why African Americans have been often found deficient was because the tests set in place to measure vitamin D levels in the body measured the levels of the binding proteins and prehormone based on a standard for light skin people.
Said tests did not take into account genetical differences, like dark skin people naturally having less of these binding proteins and the pre-vitamin D form mentioned above without this meaning they have less vitamin D. In light of recent discoveries, current tests for measuring vitamin D levels appear to be inaccurate for dark-skin people and account for why so many have been misdiagnosed with vitamin D deficiency and prescribed supplements when they might not have needed them.
Conclusion. What we should be taking from both old and new research is that melanin continues to regulate the amount of sun radiation our skin receives. The darker your skin, the better protected you are from sun radiation, while the lighter your skin, the more prone you are the suffer the side effects of sun exposure. However, neither situation excludes the necessity to wear sunscreen. It also remains true that sun radiation is the source of vitamin D produced in the skin. With sufficient sun exposure, everyone can get all the vitamin D they need, irrespective of skin color. Lastly, current tests for measuring vitamin D levels have been found to not be accurate for people with dark skin because they do not consider lower standard values for the elements measured.