In some literature , vitamin D supplementation is used in treatment of metastasis carcinoma breast .In functions of vitamin D, lowering of serum EGFR ( Her 2 neu ) is one of its functions .
The anti-proliferative effects of 1,25-dihydroxyvitamin D3 have been linked to suppression of growth stimulatory signals and potentiation of growth inhibitory signals, which lead to changes in cell cycle regulators such as p21WAF-1/CIP1 and p27kip1, cyclins and retinoblastoma protein as well as induction of apoptosis.