Swordfish Nutrition Calculator — Calories & Nutrition per Serving

Grilled swordfish delivers 68.5mcg selenium per 100g — 125% of the daily value ^[1]. A single steak (~136g) provides 93.2mcg selenium — 169% DV. Among commonly grilled fish, no other species matches this concentration: halibut provides 55.4mcg, salmon 38mcg, and tuna 36.5mcg per 100g cooked.

Even raw swordfish starts at an extraordinary 57.4mcg per 100g (104% DV) ^[1]. Cooking concentrates selenium further as water evaporates. The selenium is bound to selenomethionine in the protein matrix, making it heat-stable and highly bioavailable (85-95% absorption).

Research has confirmed that swordfish selenium content varies by ocean of origin but remains consistently high across Atlantic and Pacific populations. The high selenium is attributed to swordfish's position as an apex predator that bioaccumulates selenium from its prey chain ^[2].

Grilled swordfish provides 16.6mcg vitamin D per 100g — 83% of the daily value (20mcg by newer recommendations) ^[1]. A standard steak (~136g) delivers 22.6mcg vitamin D — 113% DV, fully covering the daily requirement from a single food item.

The vitamin D is in the D3 (cholecalciferol) form — the same form synthesized by human skin from UVB exposure. Among common fish, only eel (23.3mcg) surpasses swordfish for vitamin D content. Salmon provides 14.7mcg, and most white fish provide 0-5mcg ^[1].

Vitamin D is fat-soluble and concentrated in the fat fraction of the fish. Swordfish's moderate fat content (7.9g per 100g cooked) provides an optimal delivery matrix for vitamin D absorption — fat enough to contain substantial D3, but not so fatty that the vitamin is diluted across excessive lipid mass ^[1].

Grilled swordfish at 172 kcal per 100g occupies the middle ground between ultra-lean white fish (cod at 105, halibut at 111, mahi mahi at 109) and fatty fish (salmon at 206, mackerel at 262) ^[1]. The 7.9g fat per 100g is moderate — enough to provide richness and vitamin D, but not enough to make it a 'fatty fish.'

The fat composition is favorable: approximately 3.5g monounsaturated, 1.4g polyunsaturated (including 0.87g omega-3), and 1.9g saturated ^[1]. The monounsaturated-to-saturated ratio of 1.8:1 is similar to olive oil's profile, making swordfish's fat composition nutritionally favorable.

For a 6-oz grilled steak (170g): 292 kcal, 40g protein, 13.4g fat ^[1]. This sits precisely between a chicken breast (280 kcal, 53g protein, 6.1g fat per 170g) and a salmon fillet (350 kcal, 43.5g protein, 21.1g fat per 170g). Swordfish is the balanced middle option.

Swordfish is classified as a high-mercury species by the FDA and EPA ^[1]. The FDA advises pregnant individuals, nursing mothers, and young children to avoid swordfish entirely. For the general adult population, the recommendation is no more than 1 serving per week.

The high mercury content comes from swordfish's position as an apex predator with a long lifespan (up to 15 years). Mercury bioaccumulates through the food chain: small fish → medium fish → swordfish. The average mercury concentration in swordfish is 0.995 ppm (parts per million), compared to 0.014 ppm for salmon ^[2].

However, swordfish's high selenium content (68.5mcg/100g — the selenium-to-mercury molar ratio exceeds 1.0) provides context. Selenium binds to mercury and may reduce its bioavailability. This does not override the FDA consumption advisory, but it is a factor researchers continue to study ^[2].

Grilled swordfish delivers 9.27mg niacin per 100g — 58% of the daily value ^[1]. A single steak (~136g) provides 12.6mg niacin — 79% DV. Among all common seafood, swordfish has the highest niacin content, followed by mahi mahi (7.76mg) and halibut (7.9mg).

Combined with the B-vitamin suite — 1.62mcg B12 (68% DV) and 0.62mg B6 (36% DV) — a single swordfish steak covers over half of three different B-vitamin requirements simultaneously ^[1]. This B-vitamin density is unique among fish and rivals liver and other organ meats.

The high niacin content is consistent with swordfish's active, high-metabolism lifestyle as an open-ocean predator. Niacin is concentrated in the metabolically active dark muscle tissue that powers sustained swimming at speeds up to 60 mph ^[1].