Vitamin D3 And Calcitriol: Why The Difference Between The Two Is The Difference Between Strong and Weak Bones
You surely know by now how important Vitamin D3 is to building younger, healthier bones. But you may be surprised to learn that getting this essential vitamin to where it needs to go, in a form that your body can use, requires some additional steps.
You see, unlike other vitamins, before Vitamin D3 can perform its functions, your body must “activate” it by turning it into a hormone. This bioactivated version of the vitamin is called calcitriol. Additionally, calcitriol needs to connect with a specific receptor called the Vitamin D Receptor, or the calcitriol receptor.
When we talk about the benefits of Vitamin D3, we’re talking about the benefits of calcitriol, because unless it makes this transformation, it can’t be absorbed and used.
Today we’ll look at calcitriol’s important role in improving your bone health, its positive impact on the rest of your body, and how to increase calcitriol levels.
Calcitriol Has Many Benefits
Bioactivated Vitamin D3, or calcitriol, plays many important roles in the human body. It has been shown in medical studies1 to protect against a litany of issues including:
- Diabetes – Type 1 and 2
- Heart disease
- Multiple sclerosis
- Neurological diseases
The most relevant benefit for Savers of course, is protection against Osteoporosis, through the building of stronger bones.
How Does Calcitriol Function?
One major function of calcitriol is to connect with the Vitamin D Receptors (VDR) mentioned earlier. These VDRs, once they’ve bound with calcitriol, flip a genetic switch in your DNA. This switch, when flipped to the ‘on’ position, allows your intestines to absorb calcium by stimulating the expression of special proteins that carry it across the intestinal wall.
Otherwise it would escape your body without ever getting used! Only after calcium enters the bloodstream, it becomes bioavailable to build new bone.
If this were the only function of calcitriol, it would already rank as possibly the most important hormone at work in bone health. But this activated form of Vitamin D does even more.
Beyond Calcium Absorption
Calcitriol also regulates the creation of bone matrix proteins, mineralizing the collagen matrix in bone. This is incredibly important to building high quality, fracture-resistant bones. Savers know that when it comes to bone health, quality over quantity is the difference between strong pliable bones and thick brittle ones.
It also facilitates the out-with-the-old and in-with-the-new process of bone formation by stimulating osteoclast differentiation and calcium reabsorption of bone.1
But That’s Not All
Calcitriol has additional health benefits, such as reducing inflammation by lowering the “adaptive” immune system, while stimulating the parts of your immune system that control viral infections and help prevent autoimmune disease.2
Your immune system’s T-cells, the cells that actively fight infections, require calcitriol to activate in order to do this work. In fact, they actually seek out bioactivated Vitamin D3.3
The Vitamin D Receptors that enable your gut to absorb calcium also regulate many other important bodily functions. One VDR benefit is the activation of liver and intestinal enzymes that help your body to metabolize drugs and toxins. Our world is full of toxins that we absorb and ingest, try as we might to avoid them, so this process in incredibly important.4
Calcitriol and VDR also secrete a chemical in parts of your brain5 that increases the production of dopamine, adrenaline and noradrenaline;6 neurotransmitters that help your brain function and even improve your mood.
Additionally, there are studies showing that the enzyme that breaks down calcitriol has a positive impact on breast7 and lung cancer8, an encouraging association that suggests that activated Vitamin D facilitates this benefit.
6 Ways To Increase Your Calcitriol Levels
- Exercise has been shown to increase the activation of Vitamin D3.9 Of course Savers know that exercise also has a valuable positive impact on bone health for a multitude of other reasons.
- Omega-3 is an essential fatty acid and a powerful antioxidant with a bevy of health benefits from immune system support to decreased depression.10 For bone health, Omega-3 increases calcium absorption and reduces bone loss, helping to maintain optimal bone density. The highest food sources of omega-3s are salmon, sardines, mackerel, herring, trout, and snapper.
- Studies also reveal that Omega-6 increases calcitriol levels,10 but be wary of consuming too much of this fatty acid mainly found in processed foods and some vegetable oils. Western diets tend to consume too much Omega-6 in relation to Omega-3.
- Curcumin, a component of the common spice tumeric, also has been shown to increase calcitriol levels.11
- Vitamin E, an important antioxidant, keeps your VDRs available for calcitriol to use.10 You can increase your Vitamin E intake by consuming a variety of foods including sunflower seeds, greens (including kale), avocados, almonds, hazelnuts, broccoli, mango, and olive oil.
- Avoid excessive caffeine, since it decreases your body’s production of Vitamin D Receptors, preventing calcitriol from providing its most direct benefit, the absorption of calcium.12
Am I Already Calcitriol Deficient?
Everyone’s body is a little different, and because Vitamin D production happens naturally in the body mostly through sun exposure, where you live can impact your calcitriol levels as much as what you do.
Fortunately there are easy to recognize warning signs that you’re lacking in Vitamin D3:
- Chronic pain and muscle weakness
- Magnesium deficiency
- Impaired or low immunity
- High blood pressure
- Sadness and depression, especially when seasonal
- Age (older than 50)
I cover these indicators and how to identify them in more detail here: 6 Little Known Signs You Might Be Vitamin D Deficient.
Getting The D3 You Need
So now we’ve looked at what calcitriol is, what it does, and how it works. I’ve also listed some useful and simple ways to naturally increase your calcitriol levels and the functioning of your Vitamin D Receptors.
But if you recognize yourself in those Vitamin D deficiency signs, or you aren’t sure that you’re getting the daily required amount, you should be taking a Vitamin D3 supplement.
This is very different from a Vitamin D2 supplement. Never take Vitamin D2, which doesn’t offer the benefits of D3. Read more about the significant differences here.
I recommend taking at least the baseline 400IUs of D3 and increasing from there, depending on your sun exposure and skin tone. The Upper Intake Limit is 4000IU, so there is lots of personalization possible to get the right balance of naturally produced D3 and supplements. For strong and rejuvenated bones, you can take a minimum of 1000 IUs daily without worrying about overdosing. Read my article about identifying your personalized Vitamin D3 needs to learn more.
Calcitriol And Younger Bones
At the Save Institute we firmly believe that knowing how your body works is the first step to being able to keep it healthy. You can’t build younger bones if you don’t know how your bones get built. Today you learned about activating the Vitamin D3 you naturally produce or supplement so that it becomes calcitriol, which unlocks your body’s ability to absorb calcium.
We are a complex organism, with many interrelating systems, but at the end of the day, we can improve our health and our lives through a simple combination of best practices that include clinical nutrition, science-based supplementation, and exercising.
That’s why I created the Osteoporosis Reversal Program, so you could have an easy-to-follow blueprint that provides not just what you should do, but all the answers on why it’s the best way to build a younger you, including your bones.
Stop Worrying About Your Bone Loss
Join thousands of Savers from around the world who have reversed or prevented their bone loss naturally and scientifically with the Osteoporosis Reversal Program.
Till next time,
1 Feldman, David, et al. “The role of vitamin D in reducing cancer risk and progression” Nature Reviews Cancer. (2014). 14. 342–357. DOI: 10.1038/nrc3691. Web: http://www.nature.com/nrc/journal/v14/n5/full/nrc3691.html
2 von Essen et al. “Vitamin D controls T cell antigen receptor signaling and activation of human T cells.” Nature Immunology, 2010; Web: http://www.nature.com/ni/journal/v11/n4/full/ni.1851.html
3 Cantorna MT. 1, Zhao J, Yang L. “Vitamin D, invariant natural killer T-cells and experimental autoimmune disease.” Proc Nutr Soc. 2012 Feb;71(1):62-6. doi: 10.1017/S0029665111003193. Web: https://www.ncbi.nlm.nih.gov/pubmed/21996367
4 Reschly and M.D. Krasowski. “Evolution and Function of the NR1I Nuclear Hormone Receptor Subfamily (VDR, PXR, and CAR) with Respect to Metabolism of Xenobiotics and Endogenous Compounds.” Curr Drug Metab. 2006 May; 7(4): 349–365. Web: http://www.eurekaselect.com/55920/article
5 Cui X, Pertile R, Liu P, Eyles DW. “Vitamin D regulates tyrosine hydroxylase expression: N-cadherin a possible mediator.” Neuroscience. 2015 Sep 24;304:90-100. doi: 10.1016/j.neuroscience.2015.07.048. Epub 2015 Jul 23.
6 Darryl W. Eylesa, Steven Smithb, Robert Kinobeb , Martin Hewisond, John J. McGratha. “Distribution of the Vitamin D receptor and 1a-hydroxylase in human brain.” Journal of Chemical Neuroanatomy. 29. (2005). 21–30. http://www.easy-immune-health.com/support-files/distribution_of_vitamin_d_receptors_in_brain.pdf
7 Lopes N1, Sousa B, Martins D, Gomes M, Vieira D, Veronese LA, Milanezi F, Paredes J, Costa JL, Schmitt F. “Alterations in Vitamin D signalling and metabolic pathways in breast cancer progression: a study of VDR, CYP27B1 and CYP24A1 expression in benign and malignant breast lesions.” BMC Cancer. 2010 Sep 11;10:483. doi: 10.1186/1471-2407-10-483.
8 Chen G, Kim SH, et al. “CYP24A1 is an independent prognostic marker of survival in patients with lung adenocarcinoma.” Clin Cancer Res. 2011 Feb 15;17(4):817-26. doi: 10.1158/1078-0432.CCR-10-1789. Epub 2010 Dec 17.
9 Zittermann A1, Sabatschus O, et al. “Exercise-trained young men have higher calcium absorption rates and plasma calcitriol levels compared with age-matched sedentary controls.” Calcif Tissue Int. 2000 Sep;67(3):215-9.
10 Haussler MR1, Haussler CA, Bartik L, Whitfield GK, Hsieh JC, Slater S, Jurutka PW. “Vitamin D receptor: molecular signaling and actions of nutritional ligands in disease prevention.” Nutr Rev. 2008 Oct;66(10 Suppl 2):S98-112. Doi: 10.1111/j.1753-4887.2008.00093.x.
11 Haussler MR1, Whitfield GK, Kaneko I, Haussler CA, Hsieh D, Hsieh JC, Jurutka PW. “Molecular mechanisms of vitamin D action.” Calcif Tissue Int. 2013 Feb;92(2):77-98. doi: 10.1007/s00223-012-9619-0. Epub 2012 Jul 11.
12 Rapuri PB1, Gallagher JC, Nawaz Z. “Caffeine decreases vitamin D receptor protein expression and 1,25(OH)2D3 stimulated alkaline phosphatase activity in human osteoblast cells.” J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):368-71. Epub 2007 Jan 12.