To evaluate the associations between 1st trimester 25-hydroxyvitamin [25(OH)D] status and changes in high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), triglycerides (TG) concentrations, and TG/HDL-c and TC/HDL-c ratios throughout pregnancy.
A prospective cohort study with follow-ups at 5-13th (baseline), 20-26th, and 30-36th gestational weeks, recruited 194 pregnant women attending a public health care center in Rio de Janeiro, Brazil. Plasma 25(OH)D levels was measured in the first trimester of pregnancy using liquid chromatography-tandem mass spectrometry. The 1st trimester status of 25(OH)D was classified as adequate (=75 nmol/L) or inadequate (<75 nmol/L). Serum concentrations of TC, HDL-c and TG were measured enzymatically. Crude and adjusted (age, HOMA-IR, parity, pre-pregnancy BMI and leisure physical activity, energy intake, and gestational age) linear mixed-effects (LME) models were employed to assess the association between 1st trimester 25(OH)D inadequacy and serum lipids throughout pregnancy.
69.6% of the women had 25(OH)D inadequacy at baseline. Women with 25(OH)D inadequacy had higher mean LDL-c concentrations than those with adequacy (91.3 vs. 97.5) at baseline. Serum lipids (TC, HDL-c, LDL-c and TG) increased throughout pregnancy independently of 25(OH)D baseline status. The adjusted LME models revealed direct associations between first-trimester vitamin D inadequacy and TC (ß=9.53; 95%CI=1.12-17.94) and LDL-c (ß=9.99; 95%CI=3.62-16.36) concentrations and TC/HDL-c ratio (ß=0.16; 95%CI=0.01-0.31).
Early pregnancy 25(OH)D inadequacy was associated with detrimental changes on TC, LDL-c, TC/HDL-c ratio throughout pregnancy. Changes on these cardiovascular markers suggest the importance of ensuring the adequate vitamin D status at the beginning of pregnancy.