What it's normally used for
Vitamin B9 (Folic Acid) helps prevent major birth defects in the fetus and new-born like neural tube disorders and Spina Bifida.
Folic Acid helps create healthy red blood cells and shields the fetus and pregnant woman from anemia.
Folic Acid helps with digestion and strengthening the nervous system, and improving mental and emotional health, including overcoming depression and anxiety.
Folic Acid helps to lower the risk of serious diseases like stroke (it lowers the production of homocysteine; the amino acid that's the most responsible for stroke), heart disease, ulcerative colitis, and lung cancer.
What it does for Lucid Dreaming
Folic Acid is known for generating vivid dreams, and along with other B vitamins, it's involved in the creation and proper function of neurotransmitters within your brain.
My own results
I take Vitamins B9 (Folic Acid) after six hours of sleep and I remember more of the dream, where it seems like it's a longer dream.