Opening an Oyster

Macronutrient Content of Oysters and Mussels

(Per 100g raw edible portion unless otherwise stated)

Type of Seafood Water (g) Protein (g) Fat (g) Carbohydrate (g) Energy (Kcal) Energy (Kjl)
Oyster 85.7 10.8 1.3 2.7 65 275
Mussel 80.9 12.1 1.8 2.5 75 312

Source: Holland, B., Brown, J., & Buss, D.H., 1993. Fish and Fish Products, the third supplement to McCance & Widdowson’s The Composition of Foods (5th Edition), HMSO, London

Fat Soluble Vitamins

Vitamin A is found in quite high amounts in oil-rich fish such as herring and mackerel and in shellfish. 4oz/100g portions of these fish provide around 10 to 15% of the adult recommended daily amount (RDA) for retinol.

Vitamin E is present in significant amounts in many types of seafood, for example salmon and some shellfish, providing up to 15% of the RDA for vitamin E in a 4oz/ 100g portion. Vitamin E acts as an antioxidant protecting polyunsaturated fats and Low Density Lipoprotein (LDL) cholesterol from oxidation by free radicals – and may also have anti-inflammatory effects.

Vitamin Content of Oysters and Mussels

(Per 100g raw edible portion unless otherwise stated)

Type of Seafood Vit A (mcg) Vit D (mcg) Vit E (mg) Vit B1 (mg Vit B2 (mg) Vit B6 (mg) Vit B12 (mg)
Oyster 75 1 0.85 0.15 0.19 0.16 17
Mussel n tr 0.74 0.02 0.35 0.08 19

tr= trace amounts only; n= data not available, mg= milligrams; mcg = micrograms

Most fish contain only small amounts of Calcium although oysters, sardines and shrimps are exceptions, supplying 10 to 20% of the adult RDA in a 4oz/100g portion.

Mineral Content of Oysters and Mussels  

(Per 100g raw edible portion unless otherwise stated)

Type of Seafood Sodium (mg) Potassium (mg) Calcium (mg) Iron (mg) Zinc (mg) Iodine (mcg) Selenium (mcg)
Oyster 510 260 140 5.7 59.2 60 23
Mussel 290 320 38 5.8 2.5 140 51

tr= trace amounts only; n= data not available, mg= milligrams; mcg = micrograms

Source: Holland, B., Brown, J., & Buss, D.H., 1993. Fish and Fish Products, the third supplement to McCance & Widdowson’s The Composition of Foods (5th Edition), HMSO, London

Shellfish has high levels of Iron, similar to that of red meat. Shellfish, in particular oysters, are a rich source of Zinc – and the reputed aphrodisiac qualities of oysters are commonly attributed to the high level of Zinc present. With the adult RDA for Zinc at 9.5mg, most shellfish can make a contribution of up to 50% of this, though for other fish, the contribution is between 5 and 10%.