Most exercise occurs in the evening (when there is little or no Vitamin D)

Peak times for leisure and sports

Shading added by VitaminDWiki

See also VitaminDWiki

• People who get little noon-day sun must supplement with Vitamin D – systematic review June 2017

• 20 cent vitamin D pill similar to 2 hours sunbathing at 60 degree latitude – RCT Aug 2013

• Why do gardeners live longer (vitamin D, etc.)

• 60 minutes of sunlight needed to decrease vitamin D deficiency in sunny climate – Dec 2012

• Time in sun (in Spain) to get 4,000 IU of vitamin D: half hour in July , 2 hours in October – Sept 2016

• Indoor bicycling and 2000 IU of vitamin D lowers heart rate by 6 percent – RCT Dec 2016

  But, The Shadow Rule – you make more Vitamin D when you are taller than your shadow – 1992
  shows that lots of vitamin D can be generated in the morning at 23 degrees latitude