Vitamin K

Vitamin K and Miscarriage

Low vitamin K leads to higher miscarriage rate and birth defects

Vitamin K antagonists (VKA) are known to act as teratogens; however, there is still uncertainty about the relative risk for birth defects and the most sensitive period. In a multi-centre, observational, prospective study we compared pregnant women exposed to phenprocoumon, acenocoumarol, fluindione, warfarin and phenindione to a non-exposed control group. The rate of major birth defects after 1st trimester exposure was significantly increased (OR 3.86). Prematurity was more frequent (16.0% vs. 7.6%), mean gestational age at delivery (37.9 vs.39.4), and mean birth weight of term infants (3,166 g vs. 3,411 g) were lower compared to the controls. Using the methodology of survival analysis, miscarriage rate reached 42% vs. 14%. In conclusion, use of VKA during pregnancy increases the risk of structural defects and other adverse pregnancy outcomes.

Vitamin K and Insulin Resistance

Vitamin K lowers risk of hyperglycemia by 82%

Only the association between hyperglycemia and phylloquinone (vitamin K) intake remained significant after further adjustment for dietary confounders (OR, 0.18).

Insulin Resistance and Miscarriage

Vitamin K boosts insulin sensitivity

Higher vitamin K intake was associated with greater insulin sensitivity and glycemic status, as measured by 2-h post-OGTT insulin and glucose and ISI(0,120), after adjustment for age, sex, waist circumference, lifestyle characteristics, and diet quality [2-h post-OGTT insulin: lowest and highest quintile, 81.0 and 72.7 microU/mL, respectively; 2-h post-OGTT glucose: 106.3 and 101.9 mg/dL, respectively; ISI(0,120): 26.3 and 27.3 mg L(2)/mmol mU min]. Phylloquinone intake was not associated with fasting insulin and glucose concentrations, HOMA-IR, or HbA(1c).

http://www.ncbi.nlm.nih.gov/pubmed/18614743

Vitamin K and Inflammation

Low vitamin K associated with high bone turnover

Poor vitamin K status was associated with high concentrations of cytokines involved in bone turnover, but vitamin K supplementation did not confer a decrease in cytokine concentrations. The healthy status of this cohort may explain a lack of effect of vitamin K supplementation on cytokine concentrations.

http://www.ncbi.nlm.nih.gov/pubmed/18689371