Where Does the Vitamin D Production Process Start?
Vitamin D production starts with Ultraviolet Ray B (UVB) exposure. The UVB rays stimulate the skin cells to produce a substance called 7-dehydrocholesterol (7-DHC), which then reacts with an enzyme called cholesterol side-chain cleavage enzyme (CSC) in order to produce cholecalciferol (vitamin D3). This process is known as vitamin D synthesis. The liver or kidneys must metabolize vitamin D3 synthesized by the body in order to be utilized.
Vitamin D2 (ergocalciferol) is another form of vitamin D found in some foods and supplements. Both vitamin D3 and vitamin D2 are converted into calcidiol (25-hydroxyvitamin D) in the body. It is then further converted into a hormonally-active form called calcitriol (1,25-dihydroxycholecalciferol).
While the sun is the best way to get your vitamin D, other factors, such as your skin color, the amount of sunscreen that you use, the time of day you go out, the time of the year, or the amount of sunlight in your part of the world, can all affect your body’s vitamin D production.
Vitamin D Production for Darker Skin
The body’s largest tissue, the skin, is vital for vitamin D production. Skin color is determined by melanin, a pigment found in skin cells called melanocytes. Melanin protects the skin from ultraviolet light and assists the production of vitamin D.
People with darker skin have a more challenging time producing vitamin D. The sun’s rays do not penetrate the skin as deeply, so vitamin D production is not as efficient. The more melanin your skin has, the more difficult it is to produce vitamin D because melanin blocks UV rays from the sun from reaching your skin.
A study has shown that people with darker skin need more exposure to sunshine for vitamin D production, especially at higher latitudes. Therefore, the farther away from the equator, the less likely you are to produce vitamin D because of the lack of sun exposure.
Does Sunscreen Block Vitamin D Production?
UVB absorption in the skin is fundamental in building Vitamin D in the body. However, UVB can also cause skin issues such as sunburn, skin cancer and eye damage. To mitigate UVB damage, most people use sunscreen lotions. So you might wonder, does using sunscreen reduce the body’s ability to produce vitamin D?
Studies have shown that this is not the case. Research provided little evidence to show that sunscreen affects concentrations of vitamin D.
While spending time in the sun is the best way to produce vitamin D, sunscreen is essential to protect your skin from the harmful effects of too much UVB exposure.
Why Your Body Needs Vitamin D
Vitamin D is essential for bone health and helps the body absorb calcium and phosphorus, two vital minerals for strong bones and teeth. It also boosts your immune system and helps regulate cell growth. A lack of vitamin D can lead to rickets, osteoporosis, cancer and other health issues. The sun is the best source of vitamin D, but you can also get it from certain foods such as fatty fish, red meat, liver, eggs and fortified milk.
Getting enough vitamin D is essential for everyone, but it becomes vital for people who don’t get much sun exposure. Consider 10–30 minutes of midday sunshine several times per week to maintain healthy vitamin D levels.
A Parting Reminder
If you have darker skin, you may require a little extra than 30 minutes of sunshine per day. The amount of sun exposure should be determined by how sensitive your skin is to UV radiation and your location in the world. If the part of the world where you live does not have enough sunlight, you might consider supplements to meet your needs. Check with your doctor and get a regular blood panel done to see if your vitamin D levels are sufficient.