An interventional study of Vitamin D in Vitamin D Deficiency and Breast Milk Collection, sponsored by Mayo Clinic. Completed at 1 site in United States. Open to participants aged 1 Month to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-13.
Sponsored by Mayo Clinic · Not applicable, Interventional, and Basic science
Infants The purpose of this study is to measure breastmilk's vitamin D sulfate nutritional value in infant's saliva and digesta (gut).
Breastfeeding Mothers The purpose of this study is to measure Vitamin D sulfates in freshly expressed breastmilk samples before and after 28 days of Vitamin D supplementation in lactating mothers.
Infants
Sign the consent form to confirm participation:
You will be asked to bring a soiled diaper from the morning of the study visit. You will meet with a study team member who will collect up to 6 swabs total:
Up to 3 cheek/mouth swabs to collect saliva Up to 3 stool/anus/diaper swabs
Lactating Mothers
Sign the consent form to confirm participation:
Visit 1 (Baseline) You will meet with a study team member complete some demographic information and gestational age of the baby and birthdate, next you will have a blood draw and express breast milk in a private location, the study team will collect up to 50 ml of freshly expressed breast milk for the research study, you will be asked to bring your personal breast pump and collection container to each research visit, or manually express milk, see options below. The study team member will schedule visit 2. The study will provide the vitamin D supplement that you will take daily for 28 days.
Visit 2 (post intervention) Approximately 28 days later you will meet with a study team member, have a blood draw and express breast milk in a private location, the study team will collect up to 50 ml of freshly expressed breast milk for the research study, you will be asked to bring your personal breast pump and collection container to each research visit, or manually express milk, see options below. The study team member will ask for the container the Vitamin D supplement was in.
You have 2 options:
Option 1:
Bring along your personal breast pump and collection container to each study visit.
The study team member will collect up to 50 ml of freshly expressed breast milk for the study.
Option 2:
You do not bring along your personal breast pump and containers to each study visit, instead you will be asked to:
Manually express your breast milk into a specimen collection cup at each study visit.
801 studies on the registry are indexed under Vitamin D Deficiency; 60 are open to participants now.
This study's enrollment of 101 is above the median of 78 across 590 interventional studies indexed under Vitamin D Deficiency.
Browse Vitamin D Deficiency studies →Mayo Clinic is the lead sponsor of 3,269 studies on the registry; 672 are open to participants now.
Of its 452 completed or terminated interventional studies of FDA-regulated products, 321 (71%) have results posted.
Counted across the registry records on this site, refreshed daily.
Lactating Mothers
Inclusion Criteria:
Exclusion Criteria:
Breastfeeding Infants
Inclusion Criteria:
Exclusion Criteria:
Subjects identified as having delivered an infant and lactating will receive Vitamin D3 for 28 days.
Dietary Supplement: Vitamin D
No intervention will be administered.
Orally administered, daily dose of 5000 IU (125 mcg) Vitamin D3 for 28 days.
Also known as: cholecalciferol
Change in Vitamin D sulfate levels in breastmilk
Samples will be assessed using a Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) assay on the Agilent 6490 tandem mass spectrometer instrument.
Time frame: Baseline, Day 28
Vitamin D sulfate levels in infant saliva
Samples will first be assessed for activity using a general sulfatase activity assay, followed by a Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) assay on the Agilent 6490 tandem mass spectrometer instrument.
Time frame: Baseline
Vitamin D sulfate levels in infant digesta
Samples will first be assessed for activity using a general sulfatase activity assay, followed by a Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) assay on the Agilent 6490 tandem mass spectrometer instrument.
Time frame: Baseline
Plan to share: No
Ran from Nov 2023 to primary completion in May 2026, 29 months.
Of 168 non-industry interventional studies with no phase under Vitamin D Deficiency, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 4 and three quarters within 29. This study's 29 months is above that.
Counting every sponsor, half of 170 studies reached it within 11 months; a quarter within 4 and three quarters within 29.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Vitamin D