Vitamin D Supplementation and Dietary Recommendations

Introduction to Vitamin D

The Proceedings of the Nutrition Society recommends taking a daily vitamin D supplement of 15 μg (600 IU) to increase vitamin D levels when sunlight exposure is limited 1

Adults over 70 years may need higher doses of vitamin D, around 20 μg (800 IU) daily, as recommended by Circulation Research 2
The Proceedings of the Nutrition Society suggests that older adults take a vitamin D supplement all year round, not just during winter months 1

Vitamin D is fat-soluble, so consuming it with some dietary fat can improve absorption, according to Sports Medicine 3
Factors such as skin pigmentation, geographic location, and genetic variations in vitamin D binding protein can affect vitamin D status, as noted by Circulation Research 2

Vitamin D is essential for calcium absorption and bone mineralization, as stated by the Proceedings of the Nutrition Society 1
Adequate levels of vitamin D help maintain muscle strength and balance, according to Sports Medicine 4
Vitamin D plays a role in immune function, as reported by Sports Medicine 3
Some evidence suggests associations between vitamin D and cardiovascular health, as found by Circulation Research 2

Vitamin D levels above 180 nmol/L (72 ng/mL) can be toxic, as warned by Sports Medicine 3
Seasonal variations, such as winter sunlight in northern/southern latitudes (>35th parallel), may not provide sufficient UV-B for vitamin D synthesis, as noted by Sports Medicine 3
Factors such as sunscreen use, clothing coverage, and time of day significantly affect vitamin D synthesis from sunlight, according to MMWR Recommendations and Reports 5
People with darker skin, indoor lifestyles, or who cover their skin extensively have higher risk of deficiency, as reported by Sports Medicine 3