Combining vitamins D3 and K2 may offer significant benefits for bone health, according to recent research. These two vitamins work synergistically to support bone integrity, vascular health, and immune function. A 2025 double-blind trial involving 142 postmenopausal women with osteopenia, a condition characterized by lower bone density, explored these benefits.
Participants were given either vitamin K2 or a placebo for three years, while all received vitamin D3 and calcium. The study revealed that women who supplemented with vitamin K2 alongside vitamin D3 and calcium showed increased levels of activated osteocalcin, a protein crucial for bone building, compared to those who received only vitamin D3 and calcium. This suggests a heightened capacity for bone formation when K2 is included.
Transparent Labs, a supplement company, offers a D3 and K2 product that undergoes third-party testing to ensure quality and effectiveness. The supplement comes in veggie softgel tablets, providing 60 servings. The company states the ingredients are clean and vegan, with clinically validated dosages.
Reviewers have reported positive experiences, noting the softgels are easy to swallow and do not cause stomach issues, even when taken without food. One reviewer, a senior living in a subarctic region, shared that K2 was key to achieving optimal vitamin D levels, which had previously been a challenge with a high prescription dose.
Another long-term supplement user praised Transparent Labs, calling their products "top-notch" and highlighting their high quality compared to other brands tried over the years.