Optimal Timing and Dosage of Vitamin D for Health and Sleep Support

Wed, 15 Apr 2026 00:05:00 +0200

Vitamin D plays a crucial role in maintaining bone health, supporting immune function, and regulating sleep through its interaction with melatonin. Research suggests that taking vitamin D supplements in the morning may be more beneficial than taking them in the evening, as evening intake can interfere with melatonin production and negatively affect sleep quality. Most people cannot meet their daily vitamin D needs through food alone, making supplementation important, especially during months with limited sun exposure. Adults generally require 600 IU to 800 IU daily, though individual needs vary, and the tolerable upper limit is 4,000 IU per day to avoid toxicity. Natural sources of vitamin D include fatty fish, cod liver oil, and mushrooms, while fortified foods like milk, soy milk, and breakfast cereals can also contribute. Certain populations, including older adults, people with darker skin, those with limited sun exposure, pregnant individuals, and those with absorption issues or ce