Thanks for the info. I’d be interested in which supplements (brands, etc) you take if you feel like sharing.
K2 was first discovered by the dentist, Weston Price, in the 1930s; he called it the X-Factor in grass-fed dairy milkfat.
Many decades later, it was determined to be K2, a factor in calcium utilization, and bone (hence, teeth!) formation.
His work is largely responsible for the resurgence of the natural grass diet in cattle: The green plants supply the K1, which is turned into K2 in their guts.
Brand is not that important for D. What is important:
1. That it is D3 [Cholecalicerol], the most active form; D2 (from lanolin) used to be common on the market.
2. That it is in a good delivery form; ideally, this would be powder or liquid with a minimum of excipients or binders. Generally, capsules are superior to tablets for absorption, although that is not as much of a problem now as twenty years ago.
3. That the rest of the diet enhances its use; that would include a source of K2, such as grass-fed-source butter or milk, or a supplement: MK7 is more active and stable in the body that MK4, but both work.
N.B.
A related substance from grass-fed dairy, also discovered in the 1930s, is the Wulzen Factor. Like the X-Factor, it is a plant substance absorbed by cows from their grass feed. Unlike K2, it is not heat stable, and is destroyed by Pasteurization. “Raw” (minimally-processed) Shea Nut Butter, and fresh, raw Sugar Cane Juice (for sugar cane is a fast-growing grass), are both rich sources of Wulzen Factor.
Like K2, the Wulzen Factor [Stigmasterol, a plant cortico-steroid growth hormone], is a beneficial factor in Calcium utilization. Rosalind Wulzen called it the Anti-Stiffness [Anti-Arthritis] Factor, because she found that Pasteurized milk promoted osteo-arthritis, while raw milk mitigated osteo-arthritis, and the difference lay in the absence or presence of the Wulzen Factor.
There was a movement by scientists in the late 1940s to have the Wulzen Factor declared a Vitamin, but the USDA, which garnered money from mandated Pasteurization equipment through fees (inspections) and fines (violations), quashed it.
It's Kirkland...a Costco brand.