Inclusion Criteria:

- Breast adenocarcinoma treated by neoadjuvant or adjuvant chemotherapy within 12
months prior to study enrollment

- WHO performance status 0-1

- Age ≥18 years old

- Affiliation to a social security regime or beneficiary of equivalent social
protection

- Written informed consent provided before any study specific procedures

Complementary inclusion criterion for randomization

- Proved vitamin D deficiency as defined by serum vitamin D level lower than 30 ng/ml (75
nmol/L).

Exclusion Criteria:

- Metastatic disease

- History or presence of any other malignancy (except curatively treated nonmelanoma
skin cancer or in situ cervix carcinoma) ………….

traités dans les 5 ans précédents.

- Contraindication to calcium or cholecalciferol

- Known severe hypersensitivity to vitamin D or to calcium supplementation or to one of
the excipients.

- Disease and/or medical conditions accompanied by hypercalcaemia and/or hypercalciuria

- Calcium lithiasis and tissue calcification

- Hypervitaminosis D

- Presence of significant comorbidities:

i) Uncontrolled endocrine disease ii) Known disorders of calcium phophorus laboratory
testing iii) Proved osteopenia or osteoporosis requiring vitamin D and calcium
supplements

- Concomitant treatment with other experimental products or another vitamin D calcium
treatment

- Pregnancy, breastfeeding or of reproductive potential not using an effective
contraceptive method

- Legal inability or restricted legal ability. Medical or psychological conditions not
allowing proper study completion or informed consent signature