Vitamin A serum levels of more than 2.2 micromols may interfere with vitamin D – April 2013

Do vitamin A serum levels moderate outcome or the protective effect of vitamin D on outcome from malignant melanoma?

Clinical Nutrition, http://dx.doi.org/10.1016/j.clnu.2013.04.006,
Sinead Field s.field at leeds.ac.uk , Faye Elliott , Juliette Randerson-Moor, Kairen Kukalizch , Jennifer H. Barrett, D. Timothy Bishop, Julia A. Newton-Bishop
Section of Epidemiology & Biostatistics, Leeds Institute of Cancer Studies and Pathology, University of Leeds, Cancer Genetics Building, St. James’s University Hospital, Leeds, LS9 7TF

Background and Aims: Low serum vitamin D levels (25-OH-vit D2/3) are reported to be associated with thicker melanomas and poorer outcome. Vitamin A metabolites and vitamin D bind to the same heterodimeric receptor. We report a study testing the hypothesis that high vitamin A levels may reduce the protective effect of vitamin D on outcome.

Methods: Serum vitamin A levels were measured in 795 melanoma cases and assessed for association with Breslow thickness, overall (OS) and melanoma-specific survival (MSS), and modification of the effect of vitamin D levels on survival.

Results: Higher vitamin A levels (≥2.2μmol/l) conferred a non-significant increased risk of melanoma-specific death (adjusted HR=1.11, 95%CI(0.74-1.67), p=0.60) but not for death overall (adjusted HR=0.95, 95%CI(0.65-1.39), p=0.79).

There was reduction in the protective effect of vitamin D on OS in patients with high vitamin A levels (≥2.2μmol/l)(HR=0.99,95%CI(0.72-1.36),p=0.93) compared to patients with low levels (<2.2μmol)(HR=0.77,95%CI(0.64-0.93),p=0.007), although the difference was not statistically significant (p=0.26).

Conclusions: High vitamin A levels may reduce the protective effect of vitamin D. As sub-optimal levels of vitamin D are common in temperate climates, and are usually managed by dietary supplementation, we suggest vitamin D3 supplementation alone might be preferable for melanoma patients than preparations containing vitamin D and A.

Conference Presentation: Presented as poster at the International Melanoma Congress, Tampa, Florida

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Sorry, have not converted the serum level to amount of IU of vitamin A supplementation

See also VitaminDWiki

• All items in category Vitamin A 68 items
• 8X higher Osteoporosis risk if high level of vitamin A, vitamin D important too – Feb 2013
• Vitamin A (Cod Liver Oil) blocks vitamin D – 2008
• Vitamin D protects against lung cancer unless there is excess vitamin A – July 2012
• Vitamin D needs some vitamin A, but not too much
• Vitamins D and A, before and after birth – March 2013