Inclusion criteria:  Adult women (≥ 37 years of age); histological evidence of primary invasive breast cancer at stages I-IIIA; treatment: mastectomy followed by antiestrogen therapy; the ability to ambulate independently, that corresponded to scoring 0 or 1 of the Eastern Cooperative Oncology Performance Status  Exclusion criteria:  Any other malignancy ≤ 5 years; co-existing medical conditions (e.g., obstructive ileus) that would interfere with the study protocol; malabsorption; serious chronic diseases (e.g. advanced heart, liver or renal failure, congenital metabolic diseases); active infection; severe psychiatric illness; alcoholism or drug use; vitamin or inorganic supplement use ≤ 6 months prior to screening; vegan or macrobiotic diet ≤ 5 years prior to screening; using weight loss medications.