Pyridoxal 5'-phosphate, the active form of Vitamin B6, has been investigated for its role in alleviating symptoms of premenstrual syndrome (PMS), including PMS Type A, which is primarily characterized by anxiety, irritability, and emotional lability. The rationale for Vitamin B6 use is grounded in its involvement in neurotransmitter synthesis, particularly serotonin and gamma-aminobutyric acid (GABA), which are thought to influence mood and emotional symptoms associated with PMS.

Several randomized controlled trials and systematic reviews have assessed Vitamin B6 supplementation (typically in doses ranging from 50 to 100 mg per day) for PMS symptoms. Some studies report modest improvements in mood-related symptoms, but the quality of evidence is generally considered low to moderate due to small sample sizes, methodological limitations, and potential for bias. A 1999 Cochrane review concluded that there is some evidence for efficacy, but overall results are inconsistent and not robust. More recent analyses also highlight that while some women may benefit, the effect size is likely small, and placebo response rates are high.

In summary, there is some scientific support for the use of Vitamin B6 in treating PMS Type A symptoms, but the evidence is not strong or conclusive. Current guidelines suggest it may be considered as an option, but further high-quality studies are needed to confirm effectiveness and establish optimal dosing.