On the other hand, inadequate magnesium causes blood vessels to narrow, reducing blood flow to the pelvic region. That's what's interfering with the erection process. Men who had taken too much vitamin D consequently had problems achieving erections while using Cenforce 200 vs viagra. Anxiety, tenseness, headaches, discomfort, cramping in the muscles, and jerks in the muscles are all signs of low magnesium levels. There's no proof that getting this naturally through exposure to direct sunlight results in any kind of physical disability.