A test of a variety of Vitamin K2 capsules/tablets was done a few years back. Some had NO K2, some a lot less than stated, and a few the correct amount. BUT if you are really concerned about getting real K2 then you can make your own NATTO, it is quite easy, but...well its an acquired smell and taste.
There are a number of 'supplements' now shown to have meaningful anti cancer/cancer killing properties.
The anti cancer/cancer killing additions to Vitamin C that I take on a regular basis are
Ashwaghana (Withania somnifera), kills cancer cells in a number of way, improves effect of cancer treatment (found in Green Tea)
Theanine among other benefits its a glutamine antagonist - so for those on a Ketogenic diet it also helps starve cancer cells,
Niacin (nicotinic acid),
Gamma Vitamin E
Melatonin - inhibit cancer growth, among many other benefits, including communication between gut and liver.
Mini aspirin - can help fight cancer, among cardio benefits for those at risk.
AND now will add -
Dehydroascorbic Acid - once in a while for is different path of Vitamin C absorbtion and ability to cross blood brain barrier.
AND - when they are ready I will also make some more batches of ...
6-Shogaol (from fresh ginger) - I saw a research paper that described how they produced it, and I have done it a few times now. Its a doozy of a cancer killer (10,000 times more effective than a standard chemo drug) WHEN you can get it in contact with cancer cells. (So will try make a Liposomal version of it in due course.)https://scholar.google.com.au/scholar?q ... i=scholart