Project Summary

Vitamin D insufficiency was found to be associated with poorer survival of colorectal cancer (CRC) patients, which may be conveyed by an altered immune function. 

The aim of the “Personalized Vitamin D Supplementation” (PEVIDS) project was to assess the impact of PEVIDS on parameters of the immune system among CRC patients. In the randomized, controlled VICTORIA trial, 350 CRC patients (175 in PEVIDS and 175 in placebo group) with vitamin D insufficiency were recruited up to one year post surgery. Personalized loading doses were calculated from baseline vitamin D blood levels and body mass index (range: 40,000 - 420,000 IU) and followed by a maintenance dose of 2,000 IU vitamin D3 daily over 12 weeks. 

In the placebo group, the mean vitamin D blood level did not relevantly change (from 33 to 36 nmol/L). In the PEVIDS group, it increased from 33 to 74 nmol/L, overcoming vitamin D insufficiency in almost all patients. Furthermore, the PEVIDS group exhibited 39.3% reduction in serum interleukin-6 (IL-6) levels compared to the placebo group.

In conclusion, PEVIDS reduced IL-6, a pro-inflammatory cytokine, known to be associated with poor prognosis among CRC patients.