Vitamin D levels, dietary intake and muscle strength in women with breast cancer: a comparative study

Vitamin D status, dietary intake, and muscle mass in women with Breast Cancer: a cross-sectional, longitudinal, and randomized clinical trial study

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

REBEC

Registry ID

RBR-4mbx874

Enrollment

128

Registered

2026-03-30

Start date

2026-09-01

Completion date

Unknown

Last updated

2026-04-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Eating

Interventions

This study comprises three methodological stages: (1) a cross-sectional study to assess serum 25-hydroxyvitamin D status, dietary intake and muscle mass

(2) a longitudinal study to monitor changes in body composition and muscle strength throughout cancer treatment

and (3) a randomized, controlled, parallel, double-blind clinical trial designed to evaluate the effect of vitamin D supplementation on muscle mass in women with breast cancer, with this third stage b

Eligibility

Sex/Gender

Female

Age

45 Years to No maximum

Inclusion criteria

Inclusion criteria: Women aged 45 years or older; with breast cancer regardless of tumor histological subtype; clinical stage (I to IV), provided they are clinically stable and able to provide written informed consent (Informed Consent Form – ICF); who, at the end of Phase 2, present significant loss of lean body mass and development of vitamin D deficiency in the post-oncological treatment period

Exclusion criteria

Exclusion criteria: Presence of autoimmune diseases or neurological disorders that may hinder the interview; HIV infection; congenital muscular disorders; prolonged immobilization; significant muscle dysfunction; history of malignant neoplasms other than breast cancer; continuous use of vitamin D supplementation; contraindications to ultrasonography or other complementary examinations

Design outcomes

Primary

Measure	Time frame
To evaluate the variation in muscle thickness in women with breast cancer undergoing daily supplementation with 2,000 international units of vitamin D; an increase in muscle thickness from baseline to the end of the intervention period compared with the placebo group is expected; verified by means of B-mode ultrasonography of the quadriceps femoris and biceps brachii performed at baseline and at the end of the 12-week follow-up period; absolute and percentage differences in muscle thickness between pre- and post-intervention measurements and between the intervention and placebo groups will be observed as parameters to identify the effect of supplementation	—

Measure

Time frame

To evaluate the variation in muscle thickness in women with breast cancer undergoing daily supplementation with 2,000 international units of vitamin D; an increase in muscle thickness from baseline to the end of the intervention period compared with the placebo group is expected; verified by means of B-mode ultrasonography of the quadriceps femoris and biceps brachii performed at baseline and at the end of the 12-week follow-up period; absolute and percentage differences in muscle thickness between pre- and post-intervention measurements and between the intervention and placebo groups will be observed as parameters to identify the effect of supplementation

—

Secondary

Measure	Time frame
No secondary outcomes are expected	—

Countries

Contacts

Public ContactFábio Orsatti

Universidade Federal do Triângulo Mineiro

fabiorsatti@gmail.com+55 (34)992032366

Outcome results

None listed

Source: REBEC (via WHO ICTRP) · Data processed: May 1, 2026