Over the last few decades there have been huge controversies about whether there are widespread vitamin D deficiencies and whether vitamin D supplementation could prevent many chronic illnesses. Dr. Michael Holick holds there is a vitamin D deficiency pandemic. Dr. Holick points to association of vitamin D deficiency with a myriad of acute and chronic illnesses including preeclampsia, childhood dental caries, periodontitis, autoimmune disorders, infectious diseases, cardiovascular disease, deadly cancers, type 2 diabetes and neurological disorders.
However, a umbrella study that addressed meta-analyses that addressed studies where vitamin D supplements were given did not show much effectiveness in terms of outcomes when vitamin D was supplemented.
The views of Dr. Holick on vitamin D are a lot more correct than incorrect. Taurine, however. is required for calcium homeostasis. See also this paper. See also this paper. With eficiencies in taurine calcium homeostasis is upset. With taurine deficiencies individuals can develop severe bone absormalities even where vitamin D levels are normal.
The umbrella study as to the efficacy of vitamin D supplementation alone is also correct. Supplementation with vitamin D alone is not enough to treat ts dysregulations of calcium homeostasis due to deficiencies in taurine. To treat dysregularities in calcium homeostasis due to deficiencies in taurine, L-taurine must be supplemented with vitamin D3 and vitamin K2 MK-7. Calcium citrate is avoided.