Blood and sperm samples from 300 men over the course of a year were taken to account for seasonal differences in vitamin D levels. The results show that sperm from guys with the most vitamin D in their blood, on average, were 14 percent more likely to be wriggle rapidly than sperm from from the guys with the least amount of vitamin D. A sperm which wriggles faster can allow its tail to spin faster. A faster tail is likely to break through the outer wall of an egg and result in fertilization.
However, it can not be concluded that your vitamin D levels with either an extra day in the sun or a supplement will result in stronger sperm. But you can keep swimming strong with the following ways:
Have lots of sex: The findings from an Australian study show if men had sex (or masturbated) once daily for seven days have the percentage of their sperm with DNA damage drop from 34 percent to 26 percent by the end of the week.
Eat more folate: Folate which is also called vitamin B9 can reduce the risk of Down’s syndrome and other birth defects. So, eat such foods rich of folate as cereal, spinach and asparagus but do not eat much of soy.
Reduce consumption of trans-fats: Trans-fatty acids are believed to lower number of sperm.
Do not wear tight trousers and underwear, synthetic material and heat: All these are thought to have negative effects on fertility.
Do not frequently use hot tubs and sauna: Heat from hot tubs and sauna may lower sperm counts.
Consume less alcohol: Limit your alcohol intake because it may lower sperm count due to the production of estrogen by the liver and directly poison the sperm-producing cells of the testicle.
Pay attention to side effects of drugs: Such steroids and cytotoxic drugs that are used in cancer treatment and opiates affect male fertility.