Which vitamin is involved in the regulation of gene expression by acting as a co-factor for nuclear receptors?

A Vitamin A
B Vitamin D
C Vitamin E
D Vitamin K
Vitamin D acts as a co-factor for nuclear receptors, which regulate gene expression. This is essential for maintaining calcium and phosphorus homeostasis, as well as bone health.
D = DNA → regulates gene expression
Molecular Biology of the Cell by Alberts et al.
Vitamins Molecular Biology Gene Regulation Hard MEDICAL Confidence: high