Sunlight a nutrition tip? Yes! Try to spend some time in the sun each day. Instead of overdosing on calcium or taking Vitamin D supplements, 15-30 minutes of midday sun will garner the average person about 15,000-40,000 IU of naturally produced vitamin D! In addition to calcium absorption, sunlight plays a significant role in regulating circadian sleep patterns. It increases serotonin levels, thus improving mood.