calcium metabolism
3 interactions related to calcium metabolism
vitamin d + magnesium
Magnesium helps activate and support the function of vitamin D; low magnesium can reduce the effectiveness of vitamin D supplementation. This is a beneficial nutrient synergy rather than a harmful interaction.
vitamin d + vitamin k2
Vitamin D and vitamin K2 act synergistically on calcium metabolism: vitamin D increases calcium absorption while vitamin K2 activates osteocalcin and matrix Gla protein to direct calcium into bone and away from soft tissue. The main caution is for people taking warfarin.
vitamin d + parathyroid hormone test
Vitamin D supplementation genuinely lowers parathyroid hormone (PTH) by raising serum calcium and active vitamin D, so a PTH test drawn after recent vitamin D can read below the patient's true untreated baseline. This is a real physiologic effect and a timing/interpretation issue, not an assay artifact or a dangerous interaction.