The Sun & Brain Health

 from the NeuroNetwork for Emerging Therapies Mini Symposium Series: Here Comes the Sun

The Circadian Clock

diagram of the circadian clock from Dr. Eva Feldman
  • The master clock synchronizes tissue-specific clocks
  • Regulates melatonin release
  • Affects sleep-wake cycles
  • Regulates glucose-stimulated insulin release
  • Affects metabolism
  • Also affects the cardiovascular system, immune system, and a suite of other biological functions

The Sleep-Wake Cycle & Melatonin

Factors that disturb the sleep-wake cycle:

Vitamins & Neurotransmitters

Vitamin D3

photo of vitamin d 3
  • Brain development
  • Neural circuits
  • Sleep disorders
  • Psychiatric disorders
  • Neuro degeneration
  • General brain health

Plus a number of benefits elsewhere in the body: calcium absorption, bone mineralization, muscle strength, immune function, and more.

Dopamine & Serotonin

photo of NeuroNetwork for Emerging Therapies fellow Dr. Sarah Elzinga
photo of NeuroNetwork for Emerging Therapies fellow Dr. Sarah Elzinga
  • Neurotransmitters—chemical messengers that transmit nerve signals
  • Enhance brain activity—cognition, good mood, and sleep, among others
  • Coordinate brain-body function
  • Studies show increases in dopamine and serotonin levels with respect to sunlight
  • Exercising out in the sun enhances dopamine and serotonin production


  • The daily recommended dosage of vitamin D3 is 600 IU (International Units)
  • When adding pills, take 1000-2000 IU a day, anything more is toxic

For Mental Health & Mood:

  • There is evidence to support Vitamin D3 supplementation for depression in those who are deficient
  • Particularly useful as an augmentation strategy, using it in conjunction with medication or light therapy
  • Before taking to improve depression, vitamin d3 levels should be checked
  • 15-30 min of natural sunlight, 3 times a week during peak hours (10 AM to 4 PM)
  • Foods high in vitamin D3, many are on the Mediterranean Diet (avocado, salmon, almonds, etc.)