Does Vitamin D (Vit D) affect Prostate-Specific Antigen (PSA) levels?

Effect of Vitamin D on PSA Levels in Prostate Cancer

Preliminary research suggests that vitamin D supplementation may reduce PSA levels in some prostate cancer patients, though the evidence is limited and results are mixed. 1

Evidence on Vitamin D and PSA

• Two preliminary studies indicate that vitamin D may reduce prostate-specific antigen (PSA) levels, either when given alone or in conjunction with chemotherapy, though further research is needed to determine the full effect of this treatment 1

• In a randomized clinical trial, vitamin D3 supplementation at high doses (40,000 IU/day) increased prostate tissue and serum levels of vitamin D metabolites, including calcitriol, in a dose-dependent manner 2

• This same study found that prostate calcitriol levels were inversely associated with Ki67 (a marker of cell proliferation) in both cancerous and benign prostate tissue, suggesting potential anti-proliferative effects 2

• High-dose vitamin D3 supplementation also modestly lowered both PSA and parathyroid hormone (PTH) levels compared to the 400 IU/day group 2

Mixed Results in Clinical Studies

• A small study examining flaxseed (a source of lignan phytoestrogens) showed some potentially beneficial effects on PSA levels in prostate cancer survivors, though it's unclear if these findings translate to better prognoses 1

• In a study of 26 patients with locally advanced or metastatic prostate cancer, 20% responded to vitamin D therapy with a mean PSA reduction of 45.3% and response duration of 4-5 months 3

• However, a meta-analysis of controlled clinical trials found no significant differences in PSA change from baseline between vitamin D supplementation and placebo groups 4

• A study specifically in Black men found no effect of vitamin D supplementation on free or total PSA levels across different dosing regimens (1,000,2,000, or 4,000 IU/day) 5

Potential Benefits in Active Surveillance

• In patients with low-risk prostate cancer under active surveillance, vitamin D3 supplementation at 4,000 IU/day for one year resulted in 55% of subjects showing a decrease in the number of positive cores or decrease in Gleason score on repeat biopsy 6

• No significant adverse events were associated with vitamin D3 supplementation at this dose 6

Clinical Considerations

• The role of vitamin D in prostate cancer management remains uncertain, with ongoing trials investigating its effects 1

• For prostate cancer survivors undergoing androgen-suppressive therapy who are at high risk for osteoporosis, the National Osteoporosis Foundation recommends:

  • Supplemental calcium (1200 mg/day) and vitamin D3 (800-1000 IU/day) for all men >50 years of age 1
  • Monitoring serum 25-hydroxy vitamin D levels may be appropriate when DEXA scans are performed 1

• Vitamin D supplementation should be considered in the context of bone health rather than as a primary treatment for prostate cancer or PSA management 1

Conclusion

While some preliminary evidence suggests vitamin D may have beneficial effects on PSA levels in certain prostate cancer patients, the overall evidence is mixed and insufficient to recommend vitamin D specifically for PSA management. Current guidelines primarily support vitamin D supplementation in prostate cancer patients for bone health, particularly those on androgen deprivation therapy.