Vitamins and folic acid
Take a vitamin tablet daily. This applies to the woman as well as to the man. Folic acid (0.4 mg daily) reduces the risk of having a baby with neural tube defects. Folic acid is also good for men with reduced semen quality.
In Scandinavia, man people have low levels of vitamin D during winter season. Vitamin D deficiency reduces both male and female fertility.
That the woman eats a healthy and balanced diet and takes 0.4 mg of folic acid daily from three months before treatment start and during her pregnancy. In case the woman has been pregnant with a child with neural tube defect or is taking medication against epilepsy, 5 mg folic acid might be recommended. Please, consult your GP.
You can prevent vitamin D deficiency by taking 40 micrograms of vitamin D daily from October 1st until May 1st.