Updated: Mar 21
You probably know that plants need sunlight to survive, but did you know that humans also rely on sunlight for our own form of photosynthesis?
Day 3: Human Photosynthesis
When ultraviolet B rays hit our skin, the cholesterol (remember that word from Day 2?) in our skin cells allows Vitamin D synthesis to occur. This is absolutely necessary for our gut to receive the message to absorb calcium (more on calcium on Day 4) and phosphorus - minerals that are needed for strong bones and teeth.
Vitamin D also plays a significant role in immunity and insulin regulation due to its' anti-inflammatory nature. it also enhances the job of T-cells (our body's little defense against pathogens), which, of course, helps fight illnesses like Covid-19.
Vitamin D deficiency is linked to osteoporosis, depression, cancer, and muscle weakness. Those that live in areas with low sunlight, such as Alaska or up in the northern states of the US in the winter time, should consider taking Vitamin D3 supplements in higher doses. Talk to your health care provider (or us), about the need for you to take Vitamin D. It is a soluble vitamin, which means that you can take TOO much if you are not careful. For those living near the equator, such as in Australia or Florida, be aware that sunscreen decreases the amount of ultraviolet rays your skin receives, thus lowering your absorption. If you are fair skinned, you don't need that much exposure (5 - 15 minutes without sunscreen a day is enough). If you are darker skinned, you need more.
Ultimately, if you haven't gotten your bloodwork done in a while, it is a simple test that can give you a good baseline of where you stand and if adjustments to your lifestyle is needed or if supplements are warranted. Vitamin D does not exist in food sources in significant amounts, so sunlight is definitely the body's preference. There are ways to get adequate Vitamin D through combining both food and lifestyle, so booking an appointment with a dietitian (or us) is a great idea!
Jen Pfeilfer, MS, APD
Dr. Thomas R. Schneider, Medical Director