Sun | Exposure has never been known to cause toxicity; however, risk of skin cancer increases with exposure47 |
Oily fish or fish oils | High levels of vitamin A in fish oils (cod, halibut); sometimes high levels of mercury and other toxins (dioxins) are found in fish130,131 |
Fortified foods, such as milk, soya milk, or rice milk (in some countries); cereal; orange juice | Lactose intolerance limits consumption of milk for some people; celiac disease limits consumption of cereal for some people |
Shittake mushrooms (sun-dried)91 | Beneficial for those on a strict vegan diet |
Supplements | Inexpensive (<5ยข/d for 2000 international units of vitamin D3); vitamin D2 is ergocalciferol; vitamin D3 is cholecal-ciferol, which is 1.7 times as potent as ergocalciferol |