PREDIN: Pregnancy and Vitamin D Intervention Study

Göteborg University

Status: Completed

Conditions: Pregnancy Complications; Vitamin D Deficiency; Vitamin D3 Deficiency

Treatments: Dietary Supplement: Vitamin D Supplementation 20 µg/day; Dietary Supplement: Vitamin D Supplementation 40 µg/day; Other: Usual Antenatal Care

Study type: Interventional

Funder types: Other

Identifiers

NCT05329428

2021-03871

Details and patient eligibility

About

Vitamin D deficiency is common among certain risk groups in Sweden, and occurs approximately in every tenth pregnant woman.The aim of the randomized double-blind controlled trial Pregnancy vitamin D intervention (PREDIN) is to investigate the dose of vitamin D supplementation required in achieving vitamin D sufficiency (25OHD ≥50 nmol/l) in pregnant women at risk of vitamin D deficiency. In addition, the investigators aim to examine if the overall vitamin D status and vitamin D intake have increased since the expanded vitamin D fortification program was initiated in year 2020.

Full description

The effect of maternal vitamin D in pregnancy for maternal and offspring health needs to be clarified. In observational studies, the investigators and others show associations between poor maternal vitamin D status in pregnancy and an increased risk of pregnancy complications. Poor maternal vitamin D status is also linked to impaired growth in the first year of life, and potentially also to higher risk of developing obesity in childhood. Risk factors for vitamin D deficiency in Swedish pregnant women are related to lower intake of vitamin D and to less sun exposure.

Since the evidence for positive effects of maternal vitamin D status or intake is limited, vitamin D interventions in pregnancy are warranted to clarify the causal effects of vitamin D in pregnancy and the doses required to achieve sufficient vitamin D status in deficient women. In the first trimester, pregnant women will be screened at a routine visit in the antenatal care for the risk of vitamin D deficiency using a validated questionnaire. Women who are classified as having a high risk of vitamin D deficiency will be randomized to one of three study arms: usual antenatal care, 20 µg vitamin D per day or 40 µg vitamin D per day. The participants will be followed up until delivery. Blood will be collected for analysis of vitamin D status (25OHD) at screening and in the third trimester of pregnancy. Information regarding pregnancy, gestational complication and fetal growth will be retrieved from medical records after delivery. About 500 women will be screened and their vitamin D status and vitamin D intake will be compared to a previous population-based cohort study, to investigate if the status or intake of vitamin D has increased since the expanded food fortification program was introduced.

The study hypothesis is that vitamin D status and/or vitamin D intake is related to risk of developing complications during pregnancy or delivery and that maternal supplementation with vitamin D during pregnancy will be effective in achieving vitamin D sufficiency in pregnant women at risk of vitamin D deficiency. In addition, the investigators hypothesize that the expanded vitamin D food fortification program has increased the vitamin D status and vitamin D intake of pregnant women in Gothenburg since 2013-2014.

Enrollment: 105 patients

Sex: Female

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• pregnant women in gestational week <15

Exclusion criteria

• multi-fetal pregnancy
• known disorder to the metabolism of vitamin D, calcium or phosphate (e.g. adrenal gland disorders, kidney disease)
• ongoing treatment with vitamin D of ≥10 µg/day
• difficulties understanding the study information

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

105 participants in 3 patient groups

Vitamin D Supplementation 20 µg/day

Experimental group

Description:

Dietary supplements containing 20 µg of vitamin D per day will be provided to study subjects.

Treatment:

Dietary Supplement: Vitamin D Supplementation 20 µg/day

Vitamin D Supplementation 40 µg/day

Experimental group

Description:

Dietary supplements containing 40 µg of vitamin D per day will be provided to study subjects.

Treatment:

Dietary Supplement: Vitamin D Supplementation 40 µg/day

Usual Antenatal Care

Active Comparator group

Description:

Women randomized to usual antenatal care will receive advise about vitamin D supplementation according to usual antenatal care routines.

Treatment:

Other: Usual Antenatal Care