Vitamin D's role in health and disease
What it found
Vitamin D deficiency is linked to bone problems and many other diseases, but human trials have not always shown clear benefits.
The evidence comes from a mix of people, animals and cells.
What they found
Studies in people
Bone health
Low vitamin D is strongly linked to lower calcium, poor bone mineralisation, rickets in children and osteoporosis in adults. This can lead to bone deformities, falls and fractures.
Cancer and survival
Low vitamin D is linked to higher cancer risk and lower survival. Some clinical studies suggest vitamin D supplementation may improve survival and reduce relapse in myeloid malignancies after transplant, but not lymphoid ones.
Uterine fibroids
Some clinical studies show low vitamin D levels or certain gene variants are linked to uterine fibroids. The authors suggest vitamin D might help prevent or treat them.
Animal and lab studies
Immune system
Vitamin D helps immune cells mature and can switch between different types of immune responses. It also helps produce antimicrobial peptides that fight bacteria and viruses.
Melanoma treatment
In human and hamster melanoma cells, vitamin D made the cells more sensitive to low doses of proton beam radiation.
Studies in people and animals
Blood pressure
Animal studies show vitamin D affects blood pressure regulation, but human trials and retrospective studies have not found a clear link between vitamin D levels or supplementation and high blood pressure.
What the authors conclude
“However, further large studies are still required in order to validate the potential benefits and safety of vitamin D in clinics.”
Also in their conclusions
- They say that vitamin D should be considered an important diagnostic factor, especially in deficiency.
- They note that multiple clinical trials show positive effects of vitamin D supplementation on overall health and suggest its possible use in treating several diseases, including cancer.
- They call for further large studies to validate the potential benefits and safety of vitamin D in clinics.
How it was done
Scientists wanted to understand the many roles vitamin D plays beyond bone health, and to see whether supplementing it could help prevent or treat diseases like heart disease, diabetes, autoimmune conditions and cancer.
This is a collection of eight reviews and eight research papers on vitamin D. The research includes studies in people, animals and cells, looking at how vitamin D works and what it does in the body.
What it can’t tell you
- Many of the findings come from animal or cell studies, which cannot show what happens in people.
- Human trials have not always found clear benefits, and some studies may have had suboptimal designs.
- This paper is a collection of reviews and studies, not a single new experiment, so it cannot prove cause and effect.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Medical University of Gdańsk, Poland
The paper
- Title
- Vitamin D and Human Health
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Zmijewski MA (2019). Vitamin D and Human Health. International journal of molecular sciences. doi:10.3390/ijms20010145Free full textPubMed 30609781DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error