Intro
Nutrition is, without a doubt, one of the most important aspects of good health that get left behind in this fast paced, modern world that is full of yummy foods that happen to be lacking a decent nutritional profile. Fortunately, for a developed nation that gets excited about hamburgers a little too frequently for its easy access, there is also easy access to the nutrients necessary for optimal health. While it is quite easy to “overdo it” on vitamins, supplements, juices, and enhanced beverages, it is truly a blessing that deficiencies can be taken care of in a timely fashion.
Interestingly, even with more access to information and solutions to deficiencies, doctors are estimating that 70% of Americans are Vitamin D deficient. Even more interesting, the most common source of Vitamin D is available to everyone on the continental U.S. (with exception of people living in cloudy climates). The skin synthesizes Vitamin D from sun exposure. The most sustainable nutrient source is available all day long, but Americans skin barely get a glimpse of it.
What is Vitamin D?
Vitamin D is a fat-soluble vitamin, meaning it is stored in the liver and fatty tissues of the body. The benefit of a fat-soluble vitamin is, when a person gets a reasonable amount more of a nutrient than necessary, it will be stored for later use when there is less of the nutrient available for absorption by the body.
The skin generates the D3 version of Vitamin D. There are only a few foods that contain Vitamin D and it is in the form of D2. While both are necessary for optimal health, vitamin D3 is vitally important.
When sunlight hits the skin, the UV rays convert cholesterol stored under the skin into a vitamin D pre-vitamin. This pre-vitamin will need to go through an equalizing process before it becomes vitamin D3 and can be absorbed and used by the body. Once this process is complete, the new D3 travels to the liver by the blood stream. Here it is modified for various processes to be carried out by the body.
Best Sources of Vitamin D
The best source of vitamin D is the sun, however, there are a few foods that offer vitamin D in the form of vitamin D2. Sources include fish, dairy, mushrooms, and a few fortified foods. Check out this incredibly thorough chart from health.org.
https://health.gov/dietaryguidelines/2015/guidelines/appendix-12/
Taking 10 minutes each day to expose the body to sun light is great for vitamin D levels and safe for most people.
How Vitamin D is Used in the Body
Vitamin D has several important, if not vital, functions in the human body.
Maintain Healthy Bones
Absorption of calcium in the gut is promoted by vitamin D. Vitamin D also maintains proper levels of calcium and phosphates to facilitate proper bone development and maintenance.
Maintain Mental Health
Vitamin D also regulates enzymes in the brain that are involved in the nervous system’s development. To that point, vitamin D’s place in the nervous system positions it to help protect important parts of the nervous system’s anatomy.
Maintain Strong Immune System
Vitamin D is involved in giving the immune system direction, so to speak. The immune system works by learning the characteristics of new threats in the body. There is a complicated biology that makes this possible and Vitamin D is vitally important to its proper functioning.
There are many other bodily functions requiring Vitamin D that are vital to optimal human health.
Symptoms of Vitamin D Deficiency
* NOTE: It is very important to remember that if you have any health issues or symptoms of less than optimal health, go see a health care professional. Finding symptoms online is a poor and inconsistent way to self-diagnose. The symptoms listed below are for understanding the importance of vitamin D in the human body. While there are many symptoms of vitamin D deficiency, only a few will be mentioned here. *
Bone Loss and Poor Skeletal Formation
Bone loss and poor skeletal formation is a symptom of vitamin D deficiency caused from the body’s inability to absorb required levels of calcium. Vitamin D is important to the body’s absorption and use of calcium.
Depression
Vitamin D’s importance to the nervous system’s development means a deficiency can cause mental health issues like, most notably and common, depression. It is common to have more cases of depression in geographical areas with less sunshine through much of the year.
Weak Immune System
A vitamin D deficiency can leave the immune system without proper direction. While some people may be sick more often from this deficiency, others may experience autoimmune responses, meaning their immune system will start attacking the body it is meant to protect.
Confusion Around Vitamin D, Sunlight, and Sunblock
Research is confusing. Even more confusing are the translations that come from research as marketers attempt to frame data in favor of more sales. It is easy to find articles online that assert sunblock as an enemy of vitamin D synthesis by the skin. Other articles will state the opposite.
The best way around this confusion is to find a happy medium. Spend some time in the sun each day. 10 to 15 minutes for most people is fine, expect for those with sensitive skin. The best time to be in the sun is in the morning before it is high in the sky or later in the day but before the sun has gone down. Less direct light is much easier on the skin and more of the harmful radiation will be filtered out by the atmosphere. After a little time in the sun, apply sunscreen to protect the skin from any more harmful sun exposure.
* NOTE: If your skin is more sensitive to sunlight, receive specific instruction from a health care provider. *
Conclusion
Vitamin D is vitally important to human health. With nearly 70% of Americans deficient in this critically important nutrient, it is to the detriment of societal interactions that people get outside more. Vitamin D deficiency can make anyone miserable. Too many unhappy people and what you have is a grumpy nation.
It is important to know that NOT ALL people with vitamin D deficiency will experience symptoms quickly after becoming deficient. A person can be deficient without symptoms. People not eating foods with vitamin D on a regular basis and/or getting out in the sun on a regular basis might consider having a conversation with their health care provider.
Sources
https://health.gov/dietaryguidelines/2015/guidelines/appendix-12/
https://ods.od.nih.gov/factsheets/Vitamin%20D-HealthProfessional/
https://www.sciencedirect.com/topics/neuroscience/7-dehydrocholesterol