Vitamin B6 and Cardiovascular Disease

Abstract

While overt vitamin B6 deficiency is not a frequent finding nowadays in medical practice, evidence suggests that insufficiency of this vitamin is rather widespread in a quite large portion of the population such as the elderly or in not unusual conditions such as that of alcohol addiction. Moreover, a mild deficiency in B6 vitamin is a state that may be associated with an increased risk of cardiovascular disease. Epidemiologic evidence from case control and prospective studies have suggested that low dietary intake or reduced blood concentrations of vitamin B6 is associated with an increased risk of cardiovascular disease, although most recent trials demonstrated the ineffectiveness of vitamin B6 supplementation on the prevention of cardiovascular events recurrence. Due to limited and somewhat inconsistent data together with the ample variety of critical functions in which vitamin B6 is involved in the human body, it is very challenging to attempt at establishing a cause and effect relationship between vitamin B6 and risk of cardiovascular disease as it is to delineate the exact mechanism(s) by which vitamin B6 may modulate such risk. In the present chapter we review the currently available knowledge deriving from both epidemiological and mechanistic studies designed to define potential candidate mechanisms for the association of vitamin B6 impairment and risk of cardiovascular disease development.

The kynurenine pathway is activated in human obesity and shifted toward kynurenine monooxygenase activation

“…In women from the ABOS cohort, quinolinic acid levels were less correlated with BMI than K / T ratio and kynurenine levels which probably directly reflect IDO1 activity and the inflammation encountered in obesity. In addition to inflammation, vitamin B6 deficiency observed in obesity, as well as in cardiovascular diseases , may also exacerbate KP shift toward downstream KMO activation . Recently, inflammatory cytokines were shown to increase the expression of KP enzymes and KPm production in rat pancreatic islets and this observation highlights the need to evaluate KPm potential relationships with pancreas physiology .…”

Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B6, B12, D, and E

“…Because of its central importance in amino acid metabolism, requirements and reference intakes for vitamin B 6 are usually expressed per gram of protein intake (Bender, 1994). While overt vitamin B 6 deficiency is not a frequent finding nowadays in medical practice, evidence suggests that insufficiency of this vitamin is rather widespread in a quite large portion of the American population, especially in the elderly and in individuals with an alcohol addiction (Friso et al, 2012). …”

Dietary Vitamin B6 Intake Associated with a Decreased Risk of Cardiovascular Disease: A Prospective Cohort Study

“…Certain nutrients have long been highlighted as modifiable risk factors for CVD [5,6]. Previous studies have investigated the possible biological mechanisms underlying the beneficial effects of vitamin B 6 on CVD prevention, such as the inhibition of lipoperoxide production and decreases in the levels of homocysteine and inflammation which are known risk factors of CVD [7]. In addition, vitamin B 6 deficiency can cause hyperhomocysteinemia [8], which may lead to arterial wall damage [7].…”

“…Previous studies have investigated the possible biological mechanisms underlying the beneficial effects of vitamin B 6 on CVD prevention, such as the inhibition of lipoperoxide production and decreases in the levels of homocysteine and inflammation which are known risk factors of CVD [7]. In addition, vitamin B 6 deficiency can cause hyperhomocysteinemia [8], which may lead to arterial wall damage [7]. Nevertheless, epidemiological studies investigating the association between vitamin B 6 and CVD have shown inconsistent results [9,10,11].…”