My experience after testing very deficient and megadosing D3 for a few months was that I noticed absolutely no change.
I will thus cut down on supplementation to avoid vascular calcification.
I will thus cut down on supplementation to avoid vascular calcification.
Current good practice is to also supplement with vitamin K when taking D. This is to promote carboxylation of osteocalcin, so calcium is directed into bones rather than soft tissues[1].
Additionally, please no one take vitamin K supplements without speaking with your physician first. They’re a direct reversal agent for a class of anticoagulants, the prime example of which is warfarin. It’d suck if you accidentally had a stroke or pulmonary embolism because of a random internet comment.
With regards to vitamin K, all the versions of the supplement I've seen have a specific warning on the bottle that they're not to be used if you're also taking anticoagulants.
UVB exposure does cause cancer, that much is undisputed [1]. However, with very short exposures following a correct schedule given by a doctor, UVB phototherapy can be an efficient treatment for Vitamin D deficiency in people with certain specific illnesses like cystic fibrosis or inflammatory bowel disease that cause digestive malabsorption of vitamins. This can also be an effective treatment e.g. for psoriasis. The increase in risk seems to be negligible when used like this [2], but for people without these specific diseases a normal Vitamin D supplement is unequivocally safer.
[1] https://www.cancer.gov/publications/dictionaries/cancer-term...