Foods High in Vitamin D
Vitamin D occurs naturally in very few foods, with oily fish and eggs being the primary natural dietary sources, but these alone are insufficient to meet daily requirements—making fortified foods and supplementation essential for most people, especially older adults and those with limited sun exposure. 1, 2
Natural Food Sources
Fish and Seafood (Highest Natural Sources)
- Fatty fish such as salmon and sardines are the richest natural sources, containing 5-25 μg per 100g 2, 3
- Fish liver oils provide exceptionally high amounts at 250 μg per 100g 3
- Not all fish are equally rich in vitamin D, but many varieties provide substantial amounts 3, 4
Other Animal Products
- Egg yolks contain moderate amounts at 1.3-2.9 μg per 100g 2, 3
- Offal and liver (beef liver, organ meats) provide considerable amounts of vitamin D 3, 5, 4
- Cheese contains 1.3-2.9 μg per 100g 3
- Dark chocolate provides approximately 4 μg per 100g 3
Plant-Based Sources (Limited)
- Mushrooms can contain 21.1-58.7 μg per 100g when exposed to UV light 3
- Reindeer lichen contains 87 μg per 100g (though rarely consumed) 3
Fortified Foods (Critical for Adequate Intake)
Since natural food sources are insufficient to meet daily requirements, fortified foods are essential for achieving adequate vitamin D intake. 1, 2
Commonly Fortified Products
- Breakfast cereals (fortified varieties) 1, 2, 6
- Milk and dairy products (yogurt, fortified milk) 2, 3, 5
- Fat spreads and margarine 3
- Orange juice (fortified) 2, 3
- Plant-based beverages (fortified) 3
Important caveat: In countries like Ireland where food fortification is voluntary, fortified foods alone remain insufficient to achieve adequate intakes, making supplementation necessary. 1
Supplementation Requirements
General Adult Population
- Adults aged 1-70 years: 15 μg (600 IU) daily 7, 2
- Adults over 70 years: 20 μg (800 IU) daily 7, 2
- Older adults living independently: 15 μg daily supplement all year round (not just winter) 1, 7
Special Populations at Higher Risk
High-risk groups requiring particular attention to supplementation include: 2
- Individuals with dark skin pigmentation (reduced vitamin D synthesis from sunlight)
- Those living in Northern latitudes (>35th parallel with insufficient winter UV-B)
- People with indoor lifestyles or extensive clothing coverage
- Elderly individuals, especially those in long-term residential care 1
- Patients with gastrointestinal disorders affecting fat absorption (vitamin D is fat-soluble) 7
Safety Considerations
- Safe upper limit: 4000 IU daily 2
- Toxic levels: Above 180 nmol/L (72 ng/mL) serum concentration 7
- Consuming vitamin D with dietary fat improves absorption since it is fat-soluble 7
Key Clinical Pitfalls
Common mistake: Relying solely on dietary sources without supplementation. Even with optimal food choices including fatty fish and fortified products, dietary intake alone cannot meet recommended levels for most individuals, particularly older adults and those with limited sun exposure. 1, 5, 8
Monitoring recommendation: Annual serum 25-hydroxyvitamin D monitoring, with repeat testing 3-6 months after dosage changes, targeting minimum levels of 50 nmol/L (20 ng/mL). 1