Vitamin D, a generic word that encompasses many different chemical names such as cholecalciferol, ergocalciferol, D₃, D₂, or calcitriol, is a familiar topic of discussion in our area this time of year. It is also a bit of a misnomer, as it is so much more than a mere vitamin.  Most people who live above the 45^th parallel understand we have an increased risk of having a “sunshine vitamin” deficiency as we slog our way through the long hours of darkness.  Many people do not, however, understand the significance vitamin D has on our health and wellness.  Or, maybe you do, but you have questions and confusion surrounding the best way to supplement.  This is an important topic that is gaining ground not only with patients, but with providers, as well, and this article should help you decipher the different terms and needs surrounding this vital substance.

A Deficient Society

Vitamin D is a fat-soluble vitamin that is primarily stored in our liver and fatty tissues. Our body, through the cholesterol in our skin, converts sunshine into vitamin D₃, or cholecalciferol.  Cholecalciferol is the component that is then converted through our liver and kidneys into calcitriol, which is the chemical structure that has the effect on our health – more specifics on this in a minute.  Our body knows how to convert Vitamin D₃ into what it needs.  Where we struggle is getting it into our system; if we are lacking sunshine or if we are struggling with weight issues, we are low on D₃.  Why do weight issues matter? Know this – if the vitamin is stored (we mentioned it is stored in our fatty tissues), it is not available for use within our body.

Another fantastic fact to understand about Vitamin D is that it is considered to be a steroid hormone.  It is actually the starting point for all our steroid hormones.    Steroid hormones are a class of biochemicals in our body that include androgens, estrogens, progestogens, glucocorticoids (inflammation and immune system) and mineralcorticoids (electrolyte/fluid balance, cardiovascular).

Recent information and studies show that a very high percentage of our population is deficient in Vitamin D.  The National Health and Nutrition Examination Survey showed 90% of dark-skinned people (African-Americans, Hispanics and Asians) and 75% of light-skinned people were deficient.  Occupations also affect the status of this vitamin in our bodies.  If you work as a healthcare worker, shift-work or mainly indoors, you are at increased risk of deficiency.

The Many Faces of Vitamin D Benefits

Vitamin D is important for balancing and maintaining our health and wellness due to its effects on so many different body systems.  We are all aware of the need for vitamin D in maintaining bone health and calcium levels.  A study in 2015 showed that Vitamin D helps manage blood sugars and prevent type 2 diabetes, assisting the pancreas in releasing insulin to properly respond to blood glucose levels.  It helps protect our body from common cancers, helps us combat heart disease, increases our immune system response to common illnesses, and even decreases the risk of auto-immune disorders such as Hashimoto thyroiditis.  Along with decreasing auto-immune thyroid issues, it also supports healthy thyroid function by making it easier for the body to absorb thyroid molecules. Vitamin D helps with hormone regulation, improves mood, and increases concentration, learning and memory.

 

How to supplement and what to look for.

If you are aware of this plethora of benefits to having adequate vitamin D levels, and have already looked for supplementation, you will have noticed the many different options available.  What is vitamin D₂ versus D₃?  Why are there different options and does it matter?  The answer to the last question is yes, it does matter.   Both products contain a biochemical substance that can be used by our body, in theory, by the liver and kidney to get the active form it needs.  Egocalciferol is known as vitamin D₂ and cholecalciferol is known as vitamin D3.  Cholecalciferol is the more biologically active form of vitamin D and thus easier for our body to absorb an use.  It is important to note, if you are looking to supplement your vitamin D with foods, most vitamin-D-fortified foods, unfortunately, are made with ergocalciferol, so supplementing in this way will not give you the amounts you need to significantly affect your vitamin-D level.

The best way to get vitamin D is still sitting in the sun.  In fact, it has been shown that doing so for about 10 minutes will allow you to absorb about 10,000 units of natural vitamin D.  However, those of us that live north of the 45^th do not get direct rays of sunshine even on our sunny days – so we probably need to supplement year-round, though the dosage may change.  And, keep in mind, sunscreen will block any benefits of the sun’s rays on our vitamin D levels, so consider not putting sunscreen on for the first 10 minutes you are outside.  Secondarily, in lieu of extended (or available) sunshine, look for products that contain vitamin D₃, or cholecalciferol.  Vitamin D₃ supplementation comes in many forms and not all Vitamin D₃ products are created equal.  A person can purchase vitamin D₃ in a liquid drop form designed for use under the tongue, and in various capsule strengths based on the dose that best fits the patient.  Supplementation is not expensive, however not choosing a high quality, proven nutraceutical brand will be costly in the long run due to the potential of poor clinical effectiveness associated with an inferior product.

We recommend having a discussion with your provider to dial in the dose you need.  There are many ongoing studies to help medical professionals understand, recommend, and treat patients with appropriate dosages of Vitamin D₃.  There is still a wide debate on where proper levels should be maintained; currently < 12ng/mL is deficient and > 100ng/mL is toxic, however, a recent study showed that despite the increase in supplementation in the US, toxicity is very rare.  Recent literature suggests that maintaining a vitamin D₃ level of at least 40mg/mL can significantly reduce the risk of breast, colon, kidney, and ovarian cancer, type 1 diabetes, and bone fractures.

Generally speaking, in the Flathead Valley, many patients take anywhere from 1000 IU to 5000 IU daily.  Vitamin D₃, as mentioned, is fat-soluble and can hang around in the body for three days or longer.  Therefore, we recommend discussing your individual situation with your provider to determine your specific dose and how to properly monitor to avoid any side effects.

Checking your vitamin D₃ level is very inexpensive and can be done with an order from your provider, or in some cases may be done at select labs without a provider order.  A good rule of thumb is for every 10mg/mL you would like to raise your vitamin D₃ level, 1000 IU of vitamin D₃ supplementation should be added.  When a person decides to supplement with Vitamin D₃, it is best to “test” and not “guess” to avoid any complications and determine if the supplementation is working.

 

1. Holick MF, Chen TC. Vitamin D deficiency: a worldwide problem with health consequences. Am J Clin Nutr. 2008 Apr;87(4):1080S-6S. Vitamin D deficiency: a worldwide problem with health consequences.
2. Daniel Sowah, Xiangning Fan, Liz Dennett, Reidar Hagtvedt, and Sebastian Straube. Vitamin D levels and deficiency with different occupations: a systematic review. BMC Public Health. 2017; 17: 519. Published online 2017 Jun 22.
3. Adams JS, Hewison M. J. Update in vitamin D. Clin Endocrinol Metab. 2010 Feb;95(2):471-8. doi: 10.1210/jc.2009-1773.
4. Issa CM, Zantout MS, Azar ST. Vitamin D replacement and type 2 diabetes mellitus.  Curr Diabetes Rev. 2015;11(1):7-16.
5. MayoClinic. Vitamin D toxicity rare in people who take supplements, researchers report. Mayo Clinic and ScienceDaily. www.sciencedaily.com/releases/2015/04/150430134852.htm. Published April 30, 2015. Accessed February 10, 2020.