Group Recall (ADEK): Fat-soluble vitamins are a fixed, memorable group — A, D, E, K — everything else is water-soluble.
Vitamin D belongs to this exact group, absorbed with dietary fat and stored in fatty tissue, and is essential for calcium absorption and bone health.
Vitamin B12, C, and B6 are all water-soluble vitamins — the body doesn't store them in significant amounts, unlike the ADEK group.