Semen Quality Not Affected by Vitamin D Levels

Low vitamin D not linked to semen quality: "NEW YORK (Reuters Health) - Vitamin D deficiency is taking blame for a growing list of health problems. Weak sperm, however, may not be one of them, hints new research.

Researchers were surprised to find that the sperm-filled fluid of men with low blood levels of vitamin D was of no less quality than the semen from men with normal or high vitamin D levels.

Still, a relationship between vitamin D and semen quality can't yet be ruled out. Ramlau-Hansen pointed to some limitations of the study, including the small number of subjects who were actually vitamin-D deficient

Until further studies strengthen and refine the findings, Ramlau-Hansen can only say that more vitamin D "may not be important" for semen quality in men with vitamin levels already in the optimal range.

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Sperm health not affected by most forms of excercise

Most exercise not linked to sperm health: "NEW YORK (Reuters Health) - For most men, exercise appears to have no relationship to either the quality or quantity of sperm, according to U.S. researchers.

But they found one exception: Men who biked for at least five hours per week had fewer and less active sperm than couch potatoes.

Looking specifically at exercise, they found that men who exercised regularly -- even vigorously -- were no more likely to have problems with the quality or quantity of their sperm than men who never exercised.

However, they saw that men who said they spent at least five hours per week biking were twice as likely to have both a low sperm count, and relatively few sperm with healthy movement.

It's possible that trauma or temperature increases in the scrotum may explain the relationship between biking and semen health, "but more research is needed to investigate these mechanisms further."

It's also too early to say that regular biking caused the sperm problems, Wise cautioned. "More studies are needed to replicate our findings before they can be considered causal."

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Wait-and-see OK for some mid-risk prostate cancers

Wait-and-see OK for some mid-risk prostate cancers: "NEW YORK (Reuters Health) - More men with prostate cancer may be able to safely put off treatment in favor of monitoring the disease over time, a study of patients at one U.S. medical center suggests.

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HIV transmission may not be reduced by circumcision

Circumcision may not curb gay HIV transmission: "NEW YORK (Reuters Health) - While circumcision has been shown to lower a man's risk of contracting HIV through heterosexual sex, a new study indicates that the value of circumcision for gay and bisexual men remains questionable.

In a study of more than 1,800 men from the U.S. and Peru, researchers found that overall, the risk of contracting HIV over 18 months did not significantly differ between circumcised and uncircumcised men.

The results "indicate no overall protective benefit from male circumcision" when it comes to male-to-male HIV transmission, write the researchers.

Currently, the American Academy of Pediatrics does not recommend routine circumcision for newborns, citing insufficient evidence of overall health benefits.

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