Erythrocyte fatty acid composition does not influence levels of free, bioavailable, and total 25-hydroxy vitamin D

• In vitro, mono- and polyunsaturated fatty acids (FAs) may decrease the binding affinity of vitamin D metabolites for vitamin D-binding protein, which in turn may influence their bioavailability. FAs incorporated as phospholipids in erythrocyte (ery-) cell membranes reflect dietary intake. The purpose of this study was to investigate ery-FA composition in relation to markers for vitamin D. In healthy females (age 22.6 +/- 2.0 years) total 25(OH)D was measured by LC-MS/MS (n=78), free 25(OH)D with ELISA (n=64 of 78), and bioavailable 25(OH)D was calculated. Analysis of ery-FA composition was by gas chromatography (n=56 of 78). A strong correlation between total 25(OH)D and free 25(OH)D was seen (r=.66, p<.001), and between total-25(OH)D and bioavailable 25(OH)D (r=.68, p<.001). No correlations between 25(OH)D fractions and specific fatty acids were found, and in particular, no associations with mono- and poly-unsaturated FA compositions. All 25(OH)D fractions were correlated with leptin (total 25(OH)D (r=-.33, p<.003); bioavailable 25(OH)D (r=-.47, p<.001); free 25(OH)D (r=-.44, p<.001). Associations were found between PTH and total 25(OH)D (r=-.35, p=.002) and weaker between bioavailable 25(OH)D (r=-.35, p=.040) and free 25(OH)D (r=-.28, p=.079). All fractions of 25(OH)D appear to correlate in a similar way to PTH, BMI and body fat (leptin). No association was found between ery-FA composition and free/bioavailable 25(OH)D. It is unlikely that FAs are a strong uncoupling factor of DBP-bound 25(OH)D.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Klinisk laboratoriemedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Clinical Laboratory Medicine (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Näringslära (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Nutrition and Dietetics (hsv//eng)

Nyckelord

Erythrocyte membrane

fatty acids

leptin

lipids

parathyroid hormone

Vitamin D

Biomedical Sciences

Biomedicinsk vetenskap

Publikations- och innehållstyp

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