From the Guidelines
The recommended strength of over-the-counter vitamin D is 1000-2000 IU daily for most adults, with 1000 IU daily often sufficient for general health maintenance in individuals with normal vitamin D levels. According to the Institute of Medicine, daily dietary vitamin D intake of 600 IU in adults aged 18 to 70 years and 800 IU in adults older than 70 years should be sufficient to meet the needs of 97.5% of the adult population 1. It's essential to note that vitamin D3 (cholecalciferol) is preferred over vitamin D2 (ergocalciferol) as it's more effective at raising blood levels. Some key points to consider when taking vitamin D supplements include:
- Taking them with a meal containing some fat to enhance absorption, as vitamin D is fat-soluble
- Being aware that excessive vitamin D intake (typically above 4000 IU daily for extended periods) can lead to toxicity, causing symptoms like nausea, vomiting, weakness, and kidney problems
- Consulting with a healthcare provider before starting supplements, especially if you have specific health conditions or take medications The USPSTF has published recommendations on the use of vitamin D supplementation for the prevention of falls and fractures and vitamin supplementation for the prevention of cardiovascular disease or cancer, which can be found at www.uspreventiveservicestaskforce.org 1. However, the most recent and highest quality study, which is from 2015, provides the most relevant guidance on this topic 1.
From the Research
Recommended Vitamin D Strength
The recommended strength of vitamin D over the counter varies based on several factors, including age and health status.
- For children under 1 year, 400-1,000 IU/d is recommended 2
- For children 1-18 years, 600-1,000 IU/d is recommended 2
- For adults, the following recommendations are made:
- 800-5000 IU/day to improve musculoskeletal health 3
- 1,500-2,000 IU/d to prevent vitamin D deficiency 2
- 2000 IU/day (50 µg) to prevent and treat vitamin D deficiency 4
- 700-1000 IU per day for fall and fracture prevention in older adults 5
- 2000 IU/day (50 mcg/day) to reduce disease and mortality risks 6
- 4000-6000 IU/day to achieve serum 25(OH)D levels between 40 and 70 ng/mL for greater protection against adverse health outcomes 6
Important Considerations
- The decision to take vitamin D supplements should be based on individual needs and health status.
- Sensible sun exposure and a balanced diet can also help maintain vitamin D stores.
- It is essential to consult with a healthcare professional before taking any supplements, especially if you have a medical condition or are taking medications.
- The adequacy of vitamin D stores is determined by measuring 25-hydroxyvitamin D serum concentrations, with optimal levels ranging from 30-80 ng/ml 3 or 30-100 ng/mL 2.