Vitamin D Food Sources
| Food | Vitamin D per 100g | Notes |
|---|---|---|
| Salmon (wild) | 600–1000 IU | Best food source |
| Mackerel | 360 IU | Oily fish generally best |
| Sardines (tinned) | 270 IU | Convenient and cheap |
| Egg yolk | 40 IU | Only small amounts |
| Fortified milk / plant milk | 80–100 IU/100ml | Varies by brand |
| Fortified cereal | 50–100 IU/serving | Read label |
| Mushrooms (UV-exposed) | Up to 400 IU | Must be sun-dried or UV-treated |
Vitamin D Blood Levels — What They Mean
| Level (nmol/L) | Status | Action |
|---|---|---|
| <25 | Severe deficiency | High-dose loading regimen (e.g. 50,000 IU weekly × 8 weeks) |
| 25–50 | Deficiency | Supplementation 1000–4000 IU/day |
| 50–75 | Insufficiency | Supplementation 800–2000 IU/day |
| 75–150 | Optimal | Maintenance 800–1000 IU/day |
| >250 | Toxicity risk | Stop supplementing — rare but can cause hypercalcaemia |
Sunlight GuidelinesIn the UK: expose face and forearms to sunlight for 15–30 minutes around midday (April–September) without sunscreen. In darker skin, 30–60 minutes may be needed. In winter, supplements are essential for everyone in Northern latitudes.
Best Vitamin D Supplement Forms
| Form | Effectiveness | Notes |
|---|---|---|
| D3 (cholecalciferol) | Best — raises blood levels most | Preferred over D2 |
| D2 (ergocalciferol) | Less effective | Plant-based — suitable for vegans but less potent |
| Combined D3 + K2 | Good for bone health | K2 ensures calcium goes to bones not arteries |
| Liquid / spray D3 | Equal to tablets | Useful if swallowing tablets difficult |
Can I get too much vitamin D?
Vitamin D toxicity is rare from food or sunlight — only from very high dose supplements over prolonged periods. Symptoms include nausea, weakness, confusion, high calcium. Levels >375 nmol/L are toxic. Keep supplemental dose <4000 IU/day unless medically supervised.
Does vitamin D help with depression and immunity?
Evidence supports a link between low vitamin D and depression, and vitamin D is essential for immune function. However, supplementation in people with normal levels has not been shown to significantly improve these outcomes.
Should I take vitamin D with food?
Yes — vitamin D is fat-soluble and is absorbed best when taken with a fatty meal.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.