What Vitamins Are Shellfish High In? The Ultimate Guide

November 6, 2025 •

3 min read

According to the Food and Agriculture Organization of the United Nations, seafood provides at least 17% of the world's animal protein consumption, and shellfish offer a powerhouse of nutrients. What vitamins are shellfish high in is a crucial question for anyone seeking to boost their intake of essential B vitamins, specifically B12, alongside other key nutrients.

Quick Summary

Shellfish are highly concentrated sources of vitamin B12, vitamin E, and certain B-complex vitamins, along with essential minerals like zinc, iron, and selenium. The exact vitamin content varies by species and preparation method, with bivalves like clams and mussels often containing exceptionally high B12 levels.

Key Points

Vitamin B12: Shellfish, especially clams, oysters, and mussels, are exceptionally high in vitamin B12, which is vital for nerve function and red blood cell production.
Immune-Boosting Nutrients: Shellfish provide significant amounts of zinc and selenium, powerful antioxidants and minerals that are crucial for a healthy immune system.
Heart-Healthy Omega-3s: Beyond vitamins, shellfish are a rich source of omega-3 fatty acids, which help reduce inflammation and promote cardiovascular health.
Vitamin A & E Content: Varieties such as cooked clams offer a good supply of vitamin A, while prawns are rich in the antioxidant vitamin E.
Rich in Minerals: Many shellfish are excellent sources of essential minerals like iron, iodine, and potassium, which support blood health, metabolism, and nerve function.
Lean Protein Source: With high protein and low-calorie content, shellfish like clams and shrimp are a filling and healthy option for weight management.
Nutrient Concentration Varies: The specific vitamin and mineral content varies by species and which part of the shellfish is consumed. For example, crustacean 'brown meat' is often more nutrient-dense.

Understanding the Nutritional Power of Shellfish

Shellfish are broadly categorized into two groups: crustaceans (like shrimp, crab, and lobster) and mollusks (like clams, oysters, mussels, and scallops). Each type offers a unique nutritional profile, but many share key vitamins and minerals that contribute to overall health. Beyond just vitamins, shellfish are also excellent sources of lean protein and heart-healthy omega-3 fatty acids.

Vitamin B12: The Most Abundant Nutrient

One of the most notable features of shellfish is their incredibly high concentration of vitamin B12 (cobalamin). In fact, some bivalve mollusks, particularly clams and oysters, contain higher amounts of B12 than most meats. For reference, a 3-ounce serving of cooked clams can provide over 1,000% of the daily recommended intake (DRI) for B12, making it one of the richest natural sources available. Vitamin B12 is essential for nerve function, red blood cell formation, and DNA synthesis.

A Look at Other B-Complex Vitamins

While B12 stands out, many types of shellfish also provide other B-complex vitamins vital for converting food into energy. This includes niacin (B3), which aids in digestion and nervous system function, and riboflavin (B2), important for cellular growth and metabolism. Folate (B9) and pyridoxine (B6) can also be found, though typically in lower amounts than B12.

Essential Fat-Soluble Vitamins

Certain shellfish also contain fat-soluble vitamins, primarily vitamin A and vitamin E. Vitamin A, vital for vision and immune function, is present in various shellfish, with cooked clams being a particularly good source. The fat-soluble nature of vitamin A means it's often more concentrated in oil-rich parts of seafood. Vitamin E, a powerful antioxidant, is also found in significant amounts, especially in crustaceans like prawns.

Key Mineral Powerhouses

Alongside vitamins, shellfish deliver a strong dose of minerals, many of which work in concert with vitamins to support body functions. Some of the most notable minerals include:

Zinc: Critical for immune health, wound healing, and reproductive health. Oysters are famously one of the best dietary sources of zinc.
Iron: Essential for healthy blood cells and oxygen transport throughout the body. Clams and mussels are particularly high in iron.
Selenium: An antioxidant that helps protect cells from damage and supports the thyroid.
Iodine: Crucial for thyroid hormone regulation and metabolism, and found abundantly in many shellfish species.

The Importance of Cooking Methods

While a balanced diet is key, how you prepare shellfish can impact its nutritional value. For instance, baking or steaming is often recommended over frying or breading, which can increase calorie and fat content. Frying can also lead to the loss of beneficial omega-3 fatty acids. Choosing simpler preparation methods helps preserve the delicate vitamins and healthy fats that make shellfish so nutritious.

Comparison of Vitamins in Popular Shellfish


Shellfish Type	Highlighted Vitamins	Best For	Cooking Notes
Clams	Extremely High B12, A, C	Combating B12 deficiency, blood health	Ideal for soups and stews; retains B12 well when steamed.
Oysters	Very High B12, A, C	Immune support (high zinc), brain health	Often eaten raw, but also great grilled or baked.
Mussels	High B12, A	Overall nutrient boost, anti-inflammatory support (Omega-3s)	Excellent steamed with wine or in pasta dishes.
Crab	High B-complex vitamins, C, A, E	Immune function (good zinc), metabolic support	Can be boiled or steamed; brown meat is very nutrient-dense.
Shrimp	Good B12, E, and other B-vitamins	Lean protein source, heart health (Omega-3s)	Versatile; suitable for grilling, steaming, or sautéing.

Potential Downsides and Considerations

While nutrient-rich, shellfish also carry certain risks. Allergies are a common concern and can be severe. Additionally, some species may accumulate contaminants or heavy metals depending on the water quality in their habitat. Always source your seafood from reputable suppliers to ensure it is fresh and from a safe environment. Pregnant women, children, and individuals with health concerns should consult a doctor before significantly increasing their shellfish intake. For further reading on seafood nutrition and health, the Seafood Health Facts website offers reliable resources on sourcing and preparation.

Conclusion

Shellfish are a truly unique superfood, offering a remarkable concentration of vitamins and minerals. Species like clams, oysters, and mussels stand out for their exceptionally high levels of vitamin B12, a nutrient critical for nervous system and red blood cell health. Beyond B12, shellfish provide a variety of other B-complex vitamins, antioxidants like vitamin A and E, and essential minerals such as zinc and iron. By incorporating a variety of steamed, baked, or boiled shellfish into your diet, you can unlock a wealth of nutritional benefits for your heart, brain, and immune system.

Frequently Asked Questions

Clams contain the highest concentration of vitamin B12 among shellfish, with a single 3-ounce serving providing over 1,000% of the Daily Value.

Yes, some shellfish provide vitamin C. While not a primary source like fruits, oysters and certain crabs contain this nutrient. For example, a 100g serving of King Crab contains around 8 mg of vitamin C.

Yes, some shellfish, particularly clams and oysters, are good sources of vitamin A, which is important for vision and immune function. Cooked clams can provide a notable amount.

To preserve the most vitamins and healthy fats, it is best to steam, bake, or boil shellfish. These methods are preferable to frying, which can increase fat content and potentially reduce the concentration of beneficial omega-3s.

Yes, there is a difference. While both are nutritious, mollusks like clams and oysters are renowned for their extremely high vitamin B12 content, while crustaceans like crab and shrimp offer a broader range of B-vitamins and often high levels of antioxidant vitamin E.

Yes, the combination of omega-3 fatty acids, vitamin B12, and selenium found in many shellfish can support brain function, memory, and cognitive performance.

Yes, many shellfish, including crab and mussels, contain other B-complex vitamins such as riboflavin (B2), niacin (B3), and pyridoxine (B6), which are important for energy metabolism.