That lucky old sun just gets to roll around the sky all day. Unfortunately, most adults, and many children, do most of their rolling in office chairs, in the car, or on the floor while playing. This has a direct impact on one of the most important vitamins. I’m talking about what we should have in an adequate supply – Vitamin D.
What is it?
Vitamin D (calciferol) is a fat-soluble vitamin that occurs naturally via synthesis in our bodies from exposure to the sun. A chemical reaction takes place when ultraviolet rays reach our skin and trigger the chemical reaction to produce vitamin D. (1) Vitamin D is also naturally occurring in certain types of foods in varying amounts.
Where do we get it?
Sunlight exposure is typically the primary source of vitamin D for many people. Vitamin D is also naturally occurring in high levels in fish oils and several types of fish. It can also be found in some mushrooms that have been exposed to ultraviolet light. Other foods also contain vitamin D through fortification, or addition, of vitamin D such as juice, milk, or cereal. (3) Obviously, one of the easiest to obtain sources of vitamin D is through supplementation purchased at a retail outlet. Getting adequate levels of vitamins through food and supplementation sources is, in our modern lives, vitally important. Moreover, given the time we spend indoors for work, school, or other indoor-oriented activities.
Why do we need it?
Vitamin D serves to promote the absorption of calcium in our body which is of vital importance when it comes to having strong, healthy bones. Further, vitamin D aids in the reduction of inflammation, cell growth, and immune response – all incredibly important reasons apart from bone strength to ensure an appropriate intake of the vitamin when engaging in an exercise regimen. Vitamin D’s role in fighting COVID-19 has been implicated in studies on the duration and severity of infected individuals, underscoring the anti-inflammatory function of the vitamin and immune support. (4)
How much do I need?
How do you know if you’re deficient in vitamin D? Only blood work can provide a definitive answer to that question. However, much like tracking foods, nutrients, or macros via a food journal, taking an honest self-assessment of how much time you get to spend outside exposed to the sun should inform your need for vitamin D from other sources. While deficiencies in Vitamin D are very common worldwide (3), great you should take care to not address the problem through excessive supplementation of Vitamin D.
The Recommended Dietary Allowance (RDA) of Vitamin D for most individuals, male and female, aged 1 to 70 is 600 IU (international units), or 15mcg (micrograms). This would be on the low end of Vitamin D intake as some studies such as one conducted by the Endocrine Society recommend 1,500 to 2,000IU, or 50mcg, daily (2).
For reference, supplements of Vitamin D available for purchase in retail outlets can range from typically 1,000IU up to 5,000IU. Excessive supplementation of vitamin D can lead to symptoms such as gastrointestinal upset and muscle weakness. So you should take care not to take an excessive amount. The best approach is to discuss with your doctor your needs for vitamin D and obtain blood work if necessary. Otherwise, a balanced diet including a good measure of certain fish, fortified foods, or supplementation of vitamin D is the best approach to ensuring you meet your needs – and if you can, get outside and soak up the sun.