Rainbow trout, tuna and herring all contain more vitamin D per serving than sardines, according to research cited by Verywellhealth. Experts say most adults need 15 to 20 micrograms (600 to 800 IU) of the vitamin each day.
Rainbow trout leads the group, with a roughly 85-gram serving providing 16.2 mcg (645 IU), an amount that surpasses the daily recommended intake on its own. Tuna delivers 5.8 mcg (231 IU) per serving and is also a good source of protein, making it a practical choice for a main meal. Herring rounds out the list at 4.55 mcg (182 IU) per serving.
For those who eat fish infrequently, fortified foods can help fill the gap. Research points to milk and dairy products, yogurt, kefir, some cheeses, breakfast cereals, bread, and vitamin D-enriched orange juice. Smaller amounts are also found in eggs, flounder, tilapia, pork and some meat products.
Specialists note that fatty fish remains one of the best natural sources of vitamin D and that eating it regularly helps maintain adequate levels.
