(Self-Meta) Vitamin D supplementation ~ For and Against (Part 2 of 3)

Self-Meta Vitamin D (part 2 of 2)

**Draft WIP / Work in progress Part 2 of 3**

Following from part 1, the discussion continues in two sections – general overview of Vitamin D metabolism followed by insights from opposition to Vitamin D supplementation.

What is Vitamin D? Overview & Metabolism. 

(Condensed) Metabolism pathway.

  1. Sunlight. UV light absorbs through the skin, where the initial form 7-dehydrocholesterol is formed then transforms to the following metabolites in their respective order ~
    1. 7-dehydrochoelsterol (skin) then;
    2. 25 OHD / Calcifediol (found in blood tests) then;
    3. 1,25 OHD / Calcitriol (the end / active form).
  2. Exogenous – diet and supplemental. Both the kidney and liver converts the inactive to the active forms through the following order:
    1. Cholecalciferol (found readily in supplemental form, dry powdered version, in oil delivery vehicle eg. EVOO or sunflower oil, etc)
    2. Calcifediol (the abundant plasma version)
    3. Calcitriol. (the end / active form).
  3. Before then the complex series of calcium, phosphorus, and bone absorption /resorptions (Osteoblasts vs Osteoclast) activities becomes enabled.

(Elaborate) Metabolism pathway.

In a more elaborate overview, referring to (Arnson Y et al 2007) :

  1. The very first / initial exogenous precursor – 7-dehydrocholesterol forms within the skin upon exposure to the UVB Sunlight radiation.
  2. Then Cholecalciferol, the initial form of Vitamin D; is formed as commonly found in supplemental form ~ dry, water soluble, or with fat as delivery vehicles (EVOO, PUFAs, etc).
  3. The inactive to active form manifestation begins. Starting with:
    1. “25 OHD” ~ the Calcidiol ~ the “inactive” form. This will not be active until the enzyme 25(OH)D3‐1‐α‐hydroxylase takes place in the kidneys.
    2.  “1,25(OHD)” ~ the Calcitriol ~ is then formed by the above enzyme. This active forms then circulates and binds towards all VDR or Vitamin D  reception sites throughout all tissues; enabling all mediation of calcium, phosphorus and thereby~ bone remodelling.

Opposition of Vitamin D supplementation.

Cliff notes from the opposition.

  • Recalling from Part 1 Cliff Notes, the main rationale behind Vitamin D supplement opposition appears to be immunological and bacterial related (Timpone, P. 2010) & (Blaney, G 2017). However, to understand and translate these complex mechanisms for public knowledge remains difficult to extrapolate.
  • Within practical evidence  (Marshall Protocol)  ~ a decrease in Vitamin D supplementation (including exposure to sun) appears to play a role at improving and managing auto-immune conditions.
  • When supra physiological Vitamin D dosages are administered consistently overtime may result undesirable weakness to the innate (note: not adaptive) immune system (Marshall, T. 2018).
  • Vitamin D does not appear to be required for activating the VDR (Vitamin D receptor). Quercetin (12:16 onwards)~ a plant flavonoid found in apple, berries, and wine  appeared to be an alternative activator of VDR.
  • A paper raised by (Proal, L. 2009) suggested that Vitamin D supplementation appears to worsen asthma.
  • A clinical study and trial by (Heil, T. 2016) appears to support Marshall’s hypothesis. Here in this experiment involving 60 subjects ~ Vitamin D supplementation abstinence led improvements in metabolic syndrome. This is paradoxical considering many others proclaiming the opposite (Prasad, P. 2016) and (Melguizo-Rodriguez L et al, 2021). 
  • Another trivia raised according to a recent discussion ((Deering K et al 2020) ~ over twenty-five (25) different forms of Vitamin D was briefly mentioned. This adds further layers of complexity.
  • The alternative / opposition to Vitamin D supplementation  (Marshall, T 2018) strongly suggested that whilst Vitamin D is not strictly speaking a “nutrient” 1:55 onwards) consensus appears maintained that Vitamin D is a steroid. 

This remains WIP work in progress. To be continued on Part 3 we will proceed into the “Discussion” and Conclusion chapters of this Self-Meta.



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