The Benefits of Vitamin D

  •   Danielle L’Ami

The importance of Vitamin D to keeping you healthy. How does vitamin D3 work and what does it do, including sources and absorption.

Image of sunbather illustrating vitamin D benefits.

Vitamin D, also known as the sunshine vitamin, is crucial to our overall health and wellbeing. What makes D3 so unique is the wide range of effects it has on our body. In fact, Vitamin D3 is so powerful for our body that it is called a secosteroid (1) which means it is a special type of steroid that is very beneficial to the body. Not only does Vitamin D3 help with calcium absorption but it also has anti-inflammatory, cardiovascular and immune supporting effects (2).

How do we make Vitamin D?

First the sun has to hit our skin that is free of sunscreen. The UVB rays react with the cholesterol and Vitamin D receptors in our skin creating pre-D3. This creates Vitamin D which is then stored until the body needs it. When the body needs D3 for a process, the liver converts the Vitamin D into 25OH which can then circulate through the body. Finally, the kidneys will convert 25OH into 1, 25OH D3 which is the hormonal form of D3. 1, 25OH is very carefully controlled and is the active form of D3. (3) This form is vital to our body by maintaining our body tissues and may help reduce the development of many detrimental conditions, from heart failure to multiple sclerosis, from cancer to blood pressure reduction. In addition, Vitamin D is especially critical for bone health, as a deficiency in children can cause rickets or in adults: osteoporosis. It is also possible you may be predisposed to developing osteoporosis thanks to your genes. This is where epigenetic testing can be a big help. To learn more, read all about the health benefits of epigenetic testing.

Vitamin D receptors (VDR) are found all throughout the body: including gut, bone and kidney which is why adequate Vitamin D levels are so important for good health. The body uses the receptor sites as homes for the Vitamin D3 to dock and do its job. It is important to note that VDR is under genetic control and some people may have lower D3 levels if they have changes in the genes that code for VDR. (3)

Vitamin D3 sources and optimal blood levels

The majority of us are vitamin D deficient and we don’t even realize it unless we have had a blood test. Research suggests that optimal and protective levels are between 40 and 60 ng/ml (4). In contrast, most people have levels under 30.

While food sources like salmon, milk, leafy greens, and mushrooms all have vitamin D, these food sources have D2 which then has to be converted to D3 for the body to use it. One exception is cod liver oil which contains Vitamin D3 as well as Vitamin A, E and omega 3 (5) , making it an excellent food supplement source. However, the best source is from the sun rays. That said, a well-balanced diet of whole foods will benefit greatly, as we discuss in our post on processed foods versus whole foods.

But what if you live somewhere that doesn’t get a lot of sunshine? In addition to cod liver oil, Vitamin D3 supplements are another way to obtain adequate Vitamin D3. According to, there are two kinds to consider, vitamin D2 and vitamin D3; the first is plant-based and the second type comes, unless otherwise stated, from an animal source. Vitamin D3 is better at helping to maintain our blood level at the optimal amount but isn’t typically an option for vegans. Be sure to always take your D3 supplement with some fat to help with absorption.

Final thoughts

Vitamin D3 is a very important vitamin/hormone that is critical for health. Try to make a point of at least 20 minutes of exposed, unscreen-less skin time, at least twice a week if not more. If you have darker skin, you may need longer than 20 minutes, but always be careful not to burn and cover your skin before you turn pink. If it is winter time, or you need to raise your Vitamin D3 levels, consider starting with 2000IU* of Vitamin D3. Lastly, don’t forget to take a look at your genetic results for D3. Many people struggle to raise their D3 levels if they have a genetic tendency towards lower D3 levels and may need a higher supplement dose in addition to sun exposure.

*Be sure to check with your healthcare practitioner if that is the right dose for you.

Danielle L’Ami

Danielle L’Ami is a logophile who writes her passion and loves to connect with others through her thoughts and personal experiences. When she is not writing, you can find her watching hockey with her husband, torturing her children with new recipes, or practicing yoga to keep herself balanced.

My Toolbox Genomics empowers individuals in their healthcare journey by creating reports focused on genetic predispositions derived from published research. Test results and suggestions are intended to lead to consultation with one’s healthcare practitioner. MyTBG reports do not diagnose disease or medical conditions. Any lifestyle changes should result from consultation with qualified healthcare practitioners.