Yes, it is! If atherosclerosis occurs in the heart arteries it can lead to heart attacks or death. No matter where it occurs in the arteries it can cause serious medical problems so not something you want. Curiously as the world sufferers from a world wide epidemic of vitamin D deficiency.

It is in those areas where atherosclerosis is the worst, such as developed countries, that are also the countries where its citizens typically have the lowest vitamin D3 blood levels. Hmm! So much for higher blood levels of vitamin D3 causing some occult absorption of calcium and a direct relationship to atherosclerosis.

So how is it again that higher blood levels of vitamin D3 blood form-calcifediol cause atherosclerosis? It doesn’t, in fact, it results in the opposite. That is, it results in less. But it me try to explain how the body handles calcium. Though even in reading different sites from that of the National Institute of Health to Medscape there is no consensus as to how the body uses vitamin D in calcium metabolism. 1, 2

So, let me explain how I understand it. As I mentioned in my book and blog postings there are two on going but almost totally independent vitamin D3 systems going on in the body. But let me digress, as I realized I have not given the recommended daily allowance of calcium: 3


  • 0-6 months                        200 milligrams/day
  • 6-12 months                        260 milligrams/day
  • 1-3 years old                        700 milligrams/day
  • Young people 9-18 years old                1,300 milligrams/day
  • Adults 19-50 years old                    1,000 milligrams/day
  • Over 51 years old and older females             1,200 milligrams/day
  • 51-71 years old men                    1,000 milligrams/day
  • 14-18 years old pregnant/lactating            1,300 milligrams/day
  • 19-50 years old pregnant/lactating            1,000 milligrams/day

I will not go into the risks of too low of calcium though you can find them at the same site as I referenced for the calcium levels. So how does vitamin D3 in the active form in the blood accomplishes all what I call the hormonal effects-that is the control of calcium?

The hormonal effect is how the body through vitamin D3 controls the blood calcium level. It does this by controlling the concentration of the active form of vitamin D3-calcitriol in the blood. Which acts in a non-genomic function. That is a rapid response as often calcium and calcium bicarbonate levels must be raised quickly. 4

This form acts in its hormonal function in the blood through three main areas. These three areas are the kidneys, small intestine and skeletal bones. There the active form activates the vitamin D receptor (VDR). In the non-genomic functions like these receptors are in the cell wall. 4 This results in a much quicker response versus the genomic response where the VDR is located and activated in the nucleus.

The other vitamin D3 system, what I call the Madison-HannaH occurs inside almost all if not all the body’s cells. These are all the other actions of the active form of vitamin D3-calcitriol, apparently genomic, that occur in the cells such as effecting the immune system, metabolism and sleep for example. These two systems are essentially independent. This occurs, I believe through the control of the production of calcitriol.

I only write essentially independent as the blood form-calcifediol has some activity on the VDR.  Though calcifediol is slightly less than 1% the active form. 5
The blood form is typically bound to the vitamin D binding protein (DBP) as it has close to twice the affinity as does the active form of vitamin D3. 6
But perhaps in the free form it can migrate into and out of cells easily, affecting the VDR and its production is not tightly controlled, more on this latter.

Thus, as more is produced in the skin or ingested its concentration in the blood increases linearly. Though as the blood form calcifediol is attached to the vitamin D binding protein (DBP) this may control how it migrates into and out of cells.

Whereas the active form I believe cannot diffuse or move into or out of cells. Thus, allowing the hormonal system and the MH systems to operate independently. However, as it takes higher blood levels of the blood form of vitamin D3 before the activation of the MH system. If the levels are too high the blood form can activate the non-genomic hormonal system causing hypercalcemia.  

But the blood form only becomes an issue as far as causing hypercalcemia when blood levels of it-calcifediol are in the 300 to possibly 400 ng/ml levels as I referenced and explained in my book. Double or more of what I consider the optimal blood levels.

As the levels of the blood form rise high enough to start activation of the VDR in the cell walls of special cells that control calcium in the kidneys, small intestine and skeletal bone, the body reacts.

  1. Calcium- Fact sheet for health professionals. National Institute of Health- Office of Dietary Supplements. September 26, 2018.
  2. Medscape
  3. NIH Medline Plus winter 2011,
  4. Kidd PM. Vitamin D and K as pleotropic nutrients: Clinical importance of the skeletal and cardiovascular systems and preliminary evidence of synergism. Alternative Medicine review. 2010; 15(3): 199-222.
  5. Olson EB, Deluca HF. 25-hydroxycholecalciferol: direct effect on calcium transport. Science. 1969; 165:405-407.
  6. Teegarden D, Meredith SC, Sitrin MD. Determination of the affinity of vitamin D metabolites to serum vitamin D binding protein using assay employing lipid-coated polystyrene beads. Anal Biochem. 1991 Dec;199(2):293-9.

*The information posted above is for educational purposes only. Always check with your doctor before initiating any changes in your medical treatment. If you do not, then The Two-Minute Health Fact, Dr. Judson Somerville, nor The Optimal Dose is responsible!


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