vitamin d3
6 interactions related to vitamin d3
vitamin d3 + vitamin k2
Vitamin D3 increases calcium absorption and stimulates production of vitamin K-dependent proteins (osteocalcin, matrix Gla protein) that themselves require K2 for activation. Co-supplementation supports bone density and may reduce vascular calcification compared with D3 alone.
phenobarbital + vitamin d
Phenobarbital activates the pregnane X receptor and constitutive androstane receptor, strongly inducing hepatic CYP3A4 while also directly suppressing CYP27A1 (a 25-hydroxylase), so it both accelerates breakdown of 25-hydroxyvitamin D and slows its formation; serum 25(OH)D drops substantially over weeks to months of therapy, with osteomalacia and increased fracture risk documented in long-term users.
probiotics + vitamin d
Vitamin D and probiotics share regulatory pathways: vitamin D supports VDR expression in gut epithelium, which probiotics depend on for anti-inflammatory and barrier effects, while certain probiotic strains modestly raise serum 25(OH)D. Combined supplementation outperforms either alone for inflammatory and gut-barrier endpoints in randomized trials.
vitamin d3 + vitamin a
Vitamin D (via VDR) and vitamin A (via RXR, the obligate heterodimer partner of VDR) bind together at vitamin D response elements to drive gene transcription for immunity, bone, and epithelial differentiation. Adequate levels of both are needed for optimal signaling, but at very high doses they can antagonize each other for bone and calcium endpoints.
phenytoin + vitamin d
Phenytoin induces hepatic CYP3A4 and CYP24A1, accelerating conversion of 25-hydroxyvitamin D to inactive metabolites and lowering circulating 25(OH)D, which over time produces secondary hyperparathyroidism, reduced calcium absorption, and a measurably increased risk of osteomalacia and fractures.
carbamazepine + vitamin d
Carbamazepine activates the pregnane X receptor and strongly induces hepatic CYP3A4 and CYP24A1, accelerating catabolism of 25-hydroxyvitamin D into inactive metabolites; meta-analyses confirm consistently lower 25(OH)D in long-term users along with secondary hyperparathyroidism and reduced bone mineral density.