What are the micronutrients in fish that benefit your health?

November 14, 2025 •

4 min read

According to the Food and Agriculture Organization, fish consumption has increased significantly in recent decades, with around 88% of world fish production destined for direct human consumption in 2018. This growing demand is driven by the recognition of what are the micronutrients in fish, a rich source of essential vitamins, minerals, and fatty acids that contribute to overall health.

Quick Summary

Fish is a nutritional powerhouse, providing essential vitamins like B12 and D, minerals such as iodine, selenium, and zinc, and vital omega-3 fatty acids for brain and heart health.

Key Points

Rich in Vitamins: Fish provides essential vitamins such as B12, crucial for nerve function, and Vitamin D, vital for bone health.
Mineral Powerhouse: Seafood is an excellent source of minerals like iodine for thyroid function and selenium, a powerful antioxidant.
Omega-3 Essential Fatty Acids: Fatty fish are particularly rich in omega-3s (EPA and DHA), which are critical for heart health and cognitive function.
Fatty vs. Lean Fish: Fatty fish contain higher levels of fat-soluble vitamins (A, D) and omega-3s, while both fatty and lean fish provide significant amounts of B vitamins and minerals.
Supports Overall Health: The diverse micronutrient profile in fish aids in cognitive development, reduces the risk of chronic diseases, and strengthens bones.
Sustainable Choices Matter: Choosing sustainably sourced fish ensures the long-term availability of these nutrient-dense food sources and supports marine health.

Vitamins Found in Fish

Fish, particularly oily varieties, are packed with essential vitamins that are crucial for various bodily functions. These micronutrients play key roles in everything from bone health to nervous system function.

Vitamin B12 (Cobalamin)

Essential for: Nerve function, red blood cell formation, and DNA synthesis.
Why it matters: A deficiency can lead to anemia, fatigue, and neurological problems. Clams, mackerel, and salmon are excellent sources.

Vitamin D

Essential for: Calcium absorption and maintaining bone health. It also plays a role in immune system function.
Why it matters: Vitamin D deficiency can cause rickets in children and bone softening (osteomalacia) in adults. Fatty fish like salmon and herring are among the best dietary sources.

Vitamin A

Essential for: Vision, immune function, and cell growth.
Why it matters: It is particularly important for maintaining good eyesight and preventing vision loss. Fatty fish species and cod liver oil are rich in Vitamin A.

Minerals in Fish

Beyond vitamins, fish provide a wealth of minerals, many of which are not easily obtained from other food sources. These minerals are fundamental to metabolic processes and overall physiological health.

Iodine

Essential for: Thyroid function and the regulation of metabolism.
Why it matters: Iodine is a crucial component of thyroid hormones, and deficiency can lead to thyroid enlargement (goiter). Seafood is one of the most reliable dietary sources of iodine.

Selenium

Essential for: Antioxidant defense and thyroid function.
Why it matters: This trace mineral protects cells from damage and supports a healthy immune system. Fish like tuna and salmon are high in selenium.

Zinc

Essential for: Immune function, protein synthesis, and wound healing.
Why it matters: Zinc is vital for proper growth and development, as well as for reproductive health. Oysters and other shellfish are particularly rich sources.

Omega-3 Fatty Acids: A Unique Component

While technically a macronutrient, the omega-3 fatty acids—specifically EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid)—are often discussed alongside micronutrients due to their vital role in health and their limited presence in other food groups.

Brain Health: DHA is a major structural component of the brain and eyes, making it essential for cognitive function and visual development. Regular intake is linked to a lower risk of age-related cognitive decline.
Heart Health: EPA and DHA are known to help reduce inflammation, lower blood pressure, and decrease the risk of heart attacks and strokes.
Inflammation: The anti-inflammatory properties of omega-3s are beneficial for managing conditions like arthritis and other inflammatory diseases.

Comparison: Micronutrients in Lean vs. Fatty Fish

Understanding the differences in nutrient profiles between lean and fatty fish can help in making informed dietary choices. While both offer valuable nutrition, their fat-soluble vitamin and omega-3 content differs significantly.


Nutrient Category	Fatty Fish (e.g., Salmon, Mackerel)	Lean Fish (e.g., Cod, Haddock)
Omega-3s (EPA & DHA)	High concentration; excellent source for heart and brain health.	Lower concentration compared to oily fish; some species still provide a modest amount.
Vitamin D	Rich source, stored in the fat.	Lower amounts, though some species provide a small contribution.
Vitamin A	High levels, especially in cod liver oil and certain fatty species.	Lower concentration, though still a source.
Vitamin B12	High concentration; significant source.	High concentration; significant source.
Iodine	High concentration; excellent source.	High concentration; excellent source.
Selenium	High concentration; excellent source.	High concentration; excellent source.
Overall Fat Content	Higher fat content, with a beneficial omega-3 profile.	Very low in total fat.

The Role of Micronutrients in Fish for Overall Health

The comprehensive array of micronutrients in fish provides substantial benefits for various physiological systems. The synergy between these components makes fish a highly effective dietary choice for preventing a range of health issues.

Supporting Cognitive Development: The combination of omega-3s and B vitamins found in fish is critical for brain development, especially in infants and young children. Pregnant and breastfeeding women are often advised to consume fish for this reason.
Reducing Chronic Disease Risk: The anti-inflammatory effects of omega-3s, coupled with the antioxidant properties of selenium, can lower the risk of chronic diseases such as heart disease, diabetes, and certain cancers.
Strengthening Bones and Teeth: The Vitamin D and calcium found in some fish species, particularly when the soft bones are consumed (e.g., canned sardines), contribute to strong bone health and help prevent conditions like osteoporosis.

Sustainable Sourcing and Health

While the nutritional benefits of fish are clear, it is also important to consider the source. Many fisheries are under threat from overfishing and climate change, impacting the availability of nutrient-dense species. Choosing seafood from sustainable sources ensures the continued availability of this valuable food resource. Organizations like the Marine Stewardship Council provide helpful guides for selecting sustainably sourced seafood.

Conclusion

Fish is an irreplaceable source of a unique combination of micronutrients, including fat-soluble vitamins (A, D), B vitamins (especially B12), and essential minerals such as iodine, selenium, and zinc. These micronutrients, along with the high content of heart- and brain-healthy omega-3 fatty acids in oily fish, make seafood a cornerstone of a healthy, balanced diet. By incorporating a variety of fish species into your weekly meals, you can secure these crucial nutrients and bolster your overall health and well-being.

Visit the NHS for more nutritional information about fish and shellfish.

Frequently Asked Questions

There is no single 'most important' micronutrient, as fish offers a wide range, but omega-3 fatty acids (EPA and DHA) are particularly renowned for their unique benefits to brain and heart health, especially in fatty fish like salmon and mackerel.

No, the micronutrient content can vary significantly by fish species. Fatty fish generally have higher levels of fat-soluble vitamins (A and D) and omega-3s, while both fatty and lean fish are excellent sources of minerals like iodine and selenium and B vitamins.

While fish is a highly nutritious food, it's not a complete source for all micronutrients. A balanced diet should include a variety of foods to ensure intake of all necessary vitamins and minerals, though fish is an excellent complement.

Yes, canned fish like sardines and salmon are still great sources of micronutrients. For example, canned sardines (including the soft bones) are an excellent source of calcium, and they retain their omega-3 content.

Selenium in fish acts as a powerful antioxidant, protecting the body's cells from damage. It also plays a key role in supporting proper thyroid function.

Micronutrients in fish, particularly the omega-3 fatty acid DHA, are critical for brain health. DHA is a major component of brain tissue, and its intake is linked to better cognitive function and a lower risk of neurological decline.

Fish, especially species like clams, mackerel, and salmon, are naturally rich in Vitamin B12, which is essential for nerve function, red blood cell production, and DNA synthesis.