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Raw oysters on the half shell

Eastern oysters, raw

Checked by us One serving: 125 g · 64 kcal

Lots of vitamin B12, zinc and omega-3: EPA + DHA. Rich in 2 more nutrients: see Good for.

Limit it to once a week or less: cadmium. Worth knowing: norovirus and vibrio.

Worth knowing for some people: raw seafood in pregnancy.

Good for

How we counted this

What one serving (125 g) gives you.

Your body needs enough of each of these. Past enough, more doesn’t help. Amounts are what the food databases list, not what your body absorbs, unless a row says it was measured.

The words: “A lot” means one serving gives 20% or more of Health Canada’s daily amount, “Some” 10% to 19%, “A little” 2% to 9%, “Almost none” under 2%. Strongest word first; within a word, protein and fibre lead, then the biggest share.

A milligram (mg) is a thousandth of a gram, and a microgram (µg) a thousandth of a milligram: 1,000 µg make 1 mg.

17 more nutrients below “a lot”

How to handle it

  • Flagged for anyone eating raw or lightly cooked oysters: norovirus, with no dose figure. PHAC says lightly cooking oysters is not enough; they need 90 °C for at least 90 seconds. From December 2016 to March 2017, 331 cases of gastrointestinal illness were linked to British Columbia oysters (BC 230, Alberta 42, Ontario 59), with no deaths. A second outbreak, mid-March to mid-April 2018, caused 176 cases (BC 137, Alberta 14, Ontario 25), again no deaths, and closed with the cause of contamination not determined.

  • Flagged for anyone eating raw or undercooked oysters: Vibrio parahaemolyticus is an acute infection risk, with no dose figure; the agency advice is the finding. In 2015 Canada had 82 cases (British Columbia 60, Alberta 19, Saskatchewan 1, Ontario 2), linked mainly to oysters. PHAC names the at-risk groups: pregnant women, people with weakened immune systems, liver disease or low stomach acidity, young children and the elderly. PHAC and Health Canada advise cooking shellfish to an internal temperature of 74 °C (165 °F). The risk does not apply to canned or cooked oysters.

Watch out

How we counted this
  • Cadmium

    Limit it

    Builds up in the kidneys over years.

    Learn more

    120 g a week takes an average adult to the limit

    You’d need about 1 serving a week of this food alone to use up what an average adult’s intake leaves under the limit.

    One serving carries 54.7 µg

    How we got this

    A serving a day adds 309% to what an average adult already takes in: a share of that intake, not of the limit. With that serving every day, an average adult would be at about 290% of the limit.

    An average adult already takes in about 71% of the limit. One serving a day uses up the room left in about 1 days of the week.

    Counted from zero, with no allowance for what adults already take in from other food, 400 g a week would reach the limit.

    The dataset’s rating: Limit it: weekly or less

    Weekly or less: EFSA's 2009 tolerable weekly intake (TWI) for cadmium is 2.5 µg/kg body weight/week, 175 µg a week for 70 kg. Eaten alone, about 400 g a week of this oyster would reach it. Background is shown, not subtracted: EFSA 2012's adult mean is 1.77 µg/kg body weight/week (range 1.50–2.23), 124 µg a week or 17.7 µg a day. One 125 g serving a day carries 54.7 µg, 309% of the median adult's 17.7 µg a day (245% to 365% across the survey range) and 2.2 times the whole weekly limit if eaten daily.

    CFIA, Mercury and Metals in Fish Products, 2000-2021 (inspection results; compilation of raw data) · grade B

    Every food with cadmium

  • Zinc

    Go easy
    Learn more

    100 g a day reaches the limit

    You’d need about 0.8 servings in a day of this food alone to reach the limit.

    “Go easy” here because fewer than 2 servings at a time reach the limit; one serving on its own stays under it.

    One serving carries 49.1 mg

    This amount varies a lot from one batch to the next: the figures we hold for this food differ twofold or more. Every figure on this site uses the same one, the food’s listed value.

    How we got this

    The dataset’s rating: Go easy: can push past the limit

    May exceed: Health Canada's tolerable upper intake level (UL) for zinc in adults is 40 mg a day from all sources together. One 125 g serving of raw eastern oysters carries 49.1 mg on the USDA listing, 123% of the UL, and about 102 g in one day, eaten alone, would reach it. Zinc varies a lot between harvests: CFIA's inspection results averaged 314.6 µg/g, 39.3 mg a serving. The UL is a ceiling for long-term daily intake, so the verdict is about habitual daily oyster eating, not an occasional dozen. EFSA's own UL for adults is lower (reported as 25 mg a day).

    USDA FoodData Central, SR Legacy, 2018-04 · grade C

    Every food with zinc

  • Copper

    Go easy
    Learn more

    170 g a day reaches the limit

    You’d need about 1.4 servings in a day of this food alone to reach the limit.

    “Go easy” here because fewer than 2 servings at a time reach the limit; one serving on its own stays under it.

    One serving carries 3.57 mg

    How we got this

    The dataset’s rating: Under the limit for one serving; fewer than 2 servings reach it.

    No cap: EFSA's 2023 acceptable daily intake (ADI) for copper is 0.07 mg/kg body weight/day, 4,900 µg a day at 70 kg, all sources. A 125 g serving of raw eastern oysters carries 3.57 mg on the USDA listing, 73% of the ADI, and about 171 g in one day, eaten alone, would reach it; Health Canada's upper intake level of 10 mg a day would take about 350 g. Copper varies a lot between oysters: CFIA's inspection results averaged a third of the listing (8.72 µg/g, 1.09 mg a serving).

    USDA FoodData Central, SR Legacy, 2018-04 · grade C

    Every food with copper

  • An average adult is already at or past the limit from other food.

    Learn more

    Flagged: EFSA's 2026 tolerable weekly intake for dioxins and dioxin-like PCBs is 0.6 pg WHO 2022 toxic equivalents/kg body weight/week, 42 pg a week for 70 kg. Eaten alone, about 133 g a week would reach it at the upper bound (0.3147 pg/g) and 309 g at the lower bound (0.136). Mean adult intake of 1.87–5.64 pg/kg body weight/week (18.7–56.4 pg a day) is already above the limit; one daily serving adds 30% (lower bound over the highest background) to 210% (upper bound over the lowest). The data are 4 imported samples from 2017 (Korea 3, China 1), not necessarily the oysters sold in Canada.

    How we got this
  • Methylmercury

    Nothing to watch

    You’d need about 2.1 servings a day, every day, of this food alone to use up what an average adult’s intake leaves under the limit.

    Learn more

    One serving carries 5.2 µg (upper bound)

    How we got this

    A serving a day adds 48–743% to what an average adult already takes in: a share of that intake, not of the limit. With that serving every day, an average adult would be at about 27–156% of the limit.

    An average adult already takes in about 18% of the limit. One serving a day fits in the room left.

    Counted from zero, with no allowance for what adults already take in from other food, 2,200 g a week would reach the limit.

    Why this rating: Eating it daily comes to 875 g a week, which stays within the 1,800 g of room left before the limit.

    Women who are or may become pregnant, and children: 340 g a day.

    The dataset’s rating: Nothing to watch: under the limit

    No cap: EFSA's 2012 tolerable weekly intake (TWI) for methylmercury is 1.3 µg/kg body weight/week as mercury, 91 µg a week. Treating total mercury as methylmercury (conservative for a bivalve), about 2,188 g a week would reach it. That is a floor, since 48 of 57 results were below the detection limit and the mean uses that limit; counting them as zero gives about 30 kg. Mean adult intake is 0.24 µg/kg body weight/week, 18% of the TWI, and a daily 125 g serving carries at most 5.2 µg against a daily allowance of 13 µg. The background range, 0.07–1.08 µg/kg body weight/week, is shown, not subtracted.

    CFIA, Mercury and Metals in Fish Products, 2000-2021 (inspection results; compilation of raw data) · grade B

    Every food with methylmercury

  • Lead

    Nothing to watch

    You’d need about 9 servings a day, every day, of this food alone to double the lead an average adult already gets. No dose is known to be safe, so doubling is where we flag.

    Learn more

    A serving a day adds 12% to what an average adult already takes in. There is no limit to take a share of.

    One serving carries 4.25 µg

    How we got this

    The dataset’s rating: Nothing to watch: doesn’t double average intake

    No cap: no safe limit is set for lead (EFSA 2010 benchmark dose lower limit (BMDL01) of 0.5 µg/kg body weight/day), so no grams figure. A 125 g serving carries 4.25 µg, 12% of EFSA 2012's adult mean of 35 µg a day, so one daily serving does not double it.

    CFIA, Mercury and Metals in Fish Products, 2000-2021 (inspection results; compilation of raw data) · grade B

    Every food with lead

For some people

Worth knowing

No limit applies, so none is rated.

  • Sugar

    0.8 g of sugar in a 125 g serving, natural and added together.

    Learn more

    Shown, not rated. The food tables we read give total sugar, and few give added sugar, so the site can’t yet tell sugar added in making a food from the sugar in fruit or milk.

Also checked (nothing to act on) · 3

Noted for context, or not measured in this food yet.

  • Context only, not rated: total arsenic is mostly arsenobetaine in bivalves and has no health-based value. The inorganic share is what is rated (next row).

  • Not measured in this food yet. Not rated: no safe threshold is set for inorganic arsenic; EFSA's 2024 reference point is a benchmark dose lower limit (BMDL05) of 0.06 µg/kg body weight/day. No Canadian speciation of oysters, and no inorganic-arsenic value from an agency survey, was found, so none is rated.

  • Not measured in this food yet. Not rated: EFSA's 2009 acute reference dose (ARfD) for paralytic shellfish toxins is 0.5 µg STX equivalents/kg body weight, 30 µg for a 60 kg adult (35 µg at 70 kg) per sitting. No measured retail occurrence was found, so there is no grams figure, and none is computed at a legal limit. EFSA's own illustration: a 400 g portion at the EU limit of 800 µg/kg would give 320 µg, far over the ARfD. In Canada, control works by harvest-area closure.

Better options

How we counted this

“Better” here always means better at something the row names: more of one nutrient, more nutrients per serving, or the goal you pick. It never means better in every way.

Every amount below is for the same weight, 125 g, the size of one serving of this food, so a swap compares like with like. A serving of another food can be bigger or smaller.

Compared with the other main-dish proteins we’ve checked.

A food is listed only if it gives clearly more: at least a fifth more than this food, and at least 10% of the daily amount more.

More of what it’s good for

More vitamin B12

  • Mackerel, cooked23.8 µg in 125 g (this food: 10.9 µg) · but less zincWorth knowing: dioxins and dioxin-like PCBs · this food has it too
  • Sardines, canned in water13.5 µg in 125 g (this food: 10.9 µg) · but less zincWorth knowing: dioxins and dioxin-like PCBs · this food has it too

More omega-3: EPA + DHA

  • Mackerel, cooked1,504 mg in 125 g (this food: 391 mg) · but less zincWorth knowing: dioxins and dioxin-like PCBs · this food has it too
  • Sardines, canned in oil1,228 mg in 125 g (this food: 391 mg) · but less zincWorth knowing: dioxins and dioxin-like PCBs · this food has it too

Amounts as listed, not adjusted for how much gets in.

For zinc: Oysters, canned would lead, in the same 125 g, but is left out (Cadmium: limit it).

Chicken liver, simmered would lead this list, but it’s left out (Preformed vitamin A (retinol): limit it).

Your goal

Your goal changes only this list, not what the food gives you or what to watch.

Losing weight: fewer calories, and more nutrients, protein and fibre for each calorie.

Chicken liver, simmered would lead this list, but it’s left out (Preformed vitamin A (retinol): limit it).

Why some foods aren’t suggested

Left out: Clams, cooked (Cadmium: limit it).

Left out: Oysters, canned (Cadmium: limit it).

Left out: Farmed salmon, cooked (Histamine: go easy).

Left out: Chicken liver, simmered (Preformed vitamin A (retinol): limit it).

Bring a tracker export or describe your usual week. The same rules check all of it.

The numbers

Open every value

Name in the database: Oysters, eastern, wild, raw

How the serving was set: 125 g raw (Health Canada TRA item I.3, marine and fresh water animals without sauce: 125 g raw, 100 g cooked)

Listed nutrients, per 100 g

For each nutrient, the value this page uses is marked “used”. A row marked “second database” is another database’s figure for a matching food, kept so you can see how far databases disagree (they can differ in the samples analysed, lab methods and rounding). Its own cells are worked out from it, but none of the page’s words or scores are.

NutrientPer servingPer 100 caloriesHowSourceGrade
Omega-3: ALA0.084 g0.11 g0.16 glisted usedUS food database (USDA SR Legacy) #171978C
Calcium59 mg73.75 mg115.69 mglisted usedUS food database (USDA SR Legacy) #171978C
59 mg73.75 mg115.69 mgcopy of USDA · not usedCanadian Nutrient File 2026 #3118C
Carbohydrate2.72 g3.4 g5.33 glisted usedUS food database (USDA SR Legacy) #171978C
Choline65 mg81.25 mg127.45 mglisted usedUS food database (USDA SR Legacy) #171978C
Copper2.858 mg3.57 mg5.6 mglisted usedUS food database (USDA SR Legacy) #171978C
Energy51 kcal63.75 kcal–FDC Energy (kcal) usedUS food database (USDA SR Legacy)–
Omega-3: EPA + DHA0.313 g0.39 g0.61 glisted usedUS food database (USDA SR Legacy) #171978C
Fat1.71 g2.14 g3.35 glisted usedUS food database (USDA SR Legacy) #171978C
Cholesterol40 mg50 mg78.43 mglisted usedUS food database (USDA SR Legacy) #171978C
Fatty acids, total saturated0.474 g0.59 g0.93 glisted usedUS food database (USDA SR Legacy) #171978C
Fibre0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Folate7 µg8.75 µg13.73 µglisted usedUS food database (USDA SR Legacy) #171978C
Iron4.61 mg5.76 mg9.04 mglisted usedUS food database (USDA SR Legacy) #171978C
Magnesium18 mg22.5 mg35.29 mglisted usedUS food database (USDA SR Legacy) #171978C
Niacin (B3, niacin equivalents)2.075 mg2.59 mg4.07 mglisted usedCanadian Nutrient File 2026 #3118C
Phosphorus97 mg121.25 mg190.2 mglisted usedUS food database (USDA SR Legacy) #171978C
Potassium156 mg195 mg305.88 mglisted usedUS food database (USDA SR Legacy) #171978C
Protein5.71 g7.14 g11.2 glisted usedUS food database (USDA SR Legacy) #171978C
Riboflavin (B2)0.09 mg0.11 mg0.18 mglisted usedUS food database (USDA SR Legacy) #171978C
Selenium19.7 µg24.63 µg38.63 µglisted usedUS food database (USDA SR Legacy) #171978C
Sodium85 mg106.25 mg166.67 mglisted usedUS food database (USDA SR Legacy) #171978C
Sugars0.62 g0.78 g1.22 glisted usedUS food database (USDA SR Legacy) #171978C
Thiamin (B1)0.018 mg0.02 mg0.04 mglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin A13 µg16.25 µg25.49 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin B128.75 µg10.94 µg17.16 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin B60.031 mg0.04 mg0.06 mglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin C0 mg0 mg0 mglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin D0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin E0.85 mg1.06 mg1.67 mglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin K11 µg1.25 µg1.96 µglisted usedUS food database (USDA SR Legacy) #171978C
Water89.04 g111.3 g174.59 glisted usedUS food database (USDA SR Legacy) #171978C
Zinc39.3 mg49.13 mg77.06 mglisted usedUS food database (USDA SR Legacy) #171978C
NutrientPer 100 gPer servingPer 100 caloriesHowSourceGrade
Beta-carotene0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Ash0.82 g1.03 g1.61 glisted usedUS food database (USDA SR Legacy) #171978C
Starch0.45 g0.56 g0.88 glisted usedUS food database (USDA SR Legacy) #171978C
Sucrose0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Glucose0.62 g0.78 g1.22 glisted usedUS food database (USDA SR Legacy) #171978C
Fructose0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Maltose0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Alcohol, ethyl0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Caffeine0 mg0 mg0 mglisted usedUS food database (USDA SR Legacy) #171978C
Theobromine0 mg0 mg0 mglisted usedUS food database (USDA SR Legacy) #171978C
Energy213 kj266.25 kj417.65 kjlisted usedUS food database (USDA SR Legacy) #171978C
Galactose0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Fluoride, F40.5 µg50.63 µg79.41 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin A, IU44 iu55 iu86.27 iulisted usedUS food database (USDA SR Legacy) #171978C
Carotene, alpha0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin D (D2 + D3), International Units1 iu1.25 iu1.96 iulisted usedUS food database (USDA SR Legacy) #171978C
Vitamin D3 (cholecalciferol)0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Cryptoxanthin, beta0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Lycopene0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin K (Menaquinone-4)2.5 µg3.13 µg4.9 µglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin K (Dihydrophylloquinone)0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Folic acid0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Folate, food7 µg8.75 µg13.73 µglisted usedUS food database (USDA SR Legacy) #171978C
Folate, DFE7 µg8.75 µg13.73 µglisted usedUS food database (USDA SR Legacy) #171978C
Tryptophan0.069 g0.09 g0.14 glisted usedUS food database (USDA SR Legacy) #171978C
Threonine0.023 g0.03 g0.05 glisted usedUS food database (USDA SR Legacy) #171978C
Isoleucine0.229 g0.29 g0.45 glisted usedUS food database (USDA SR Legacy) #171978C
Leucine0.358 g0.45 g0.7 glisted usedUS food database (USDA SR Legacy) #171978C
Lysine0.381 g0.48 g0.75 glisted usedUS food database (USDA SR Legacy) #171978C
Methionine0.129 g0.16 g0.25 glisted usedUS food database (USDA SR Legacy) #171978C
Cystine0.055 g0.07 g0.11 glisted usedUS food database (USDA SR Legacy) #171978C
Phenylalanine0.207 g0.26 g0.41 glisted usedUS food database (USDA SR Legacy) #171978C
Tyrosine0.202 g0.25 g0.4 glisted usedUS food database (USDA SR Legacy) #171978C
Valine0.262 g0.33 g0.51 glisted usedUS food database (USDA SR Legacy) #171978C
Arginine0.372 g0.47 g0.73 glisted usedUS food database (USDA SR Legacy) #171978C
Histidine0.11 g0.14 g0.22 glisted usedUS food database (USDA SR Legacy) #171978C
Alanine0.271 g0.34 g0.53 glisted usedUS food database (USDA SR Legacy) #171978C
Aspartic acid0.491 g0.61 g0.96 glisted usedUS food database (USDA SR Legacy) #171978C
Glutamic acid0.675 g0.84 g1.32 glisted usedUS food database (USDA SR Legacy) #171978C
Glycine0.275 g0.34 g0.54 glisted usedUS food database (USDA SR Legacy) #171978C
Proline0.225 g0.28 g0.44 glisted usedUS food database (USDA SR Legacy) #171978C
Serine0.225 g0.28 g0.44 glisted usedUS food database (USDA SR Legacy) #171978C
Vitamin E, added0 mg0 mg0 mglisted usedUS food database (USDA SR Legacy) #171978C
Vitamin B-12, added0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Fatty acids, total trans0.034 g0.04 g0.07 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 4:00 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 6:00 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 8:00 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 10:00 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 12:00.001 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 14:00.05 g0.06 g0.1 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 16:00.319 g0.4 g0.63 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 18:00.066 g0.08 g0.13 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 20:00.002 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 18:10.168 g0.21 g0.33 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 18:20.041 g0.05 g0.08 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 18:30.084 g0.11 g0.16 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 20:40.022 g0.03 g0.04 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 22:6 n-3 (DHA)0.136 g0.17 g0.27 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 22:00.001 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 14:10.002 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 16:10.052 g0.07 g0.1 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 18:40.048 g0.06 g0.09 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 20:10.028 g0.04 g0.05 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 20:5 n-3 (EPA)0.177 g0.22 g0.35 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 22:10.001 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 22:5 n-3 (DPA)0.01 g0.01 g0.02 glisted usedUS food database (USDA SR Legacy) #171978C
Fatty acids, total monounsaturated0.253 g0.32 g0.5 glisted usedUS food database (USDA SR Legacy) #171978C
Fatty acids, total polyunsaturated0.528 g0.66 g1.04 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 15:00.011 g0.01 g0.02 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 17:00.024 g0.03 g0.05 glisted usedUS food database (USDA SR Legacy) #171978C
SFA 24:00.002 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 24:1 c0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 20:2 n-6 c,c0.003 g0 g0.01 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 17:10.003 g0 g0.01 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 20:30.006 g0.01 g0.01 glisted usedUS food database (USDA SR Legacy) #171978C
MUFA 15:10 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
PUFA 22:40.002 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Lactose0 g0 g0 glisted usedUS food database (USDA SR Legacy) #171978C
Lutein + zeaxanthin0 µg0 µg0 µglisted usedUS food database (USDA SR Legacy) #171978C
Manganese0.296 mg0.37 mg0.58 mglisted usedUS food database (USDA SR Legacy) #171978C
Niacin (B3, preformed)0.925 mg1.16 mg1.81 mglisted usedUS food database (USDA SR Legacy) #171978C
Pantothenic acid (B5)0.223 mg0.28 mg0.44 mglisted usedUS food database (USDA SR Legacy) #171978C
Retinol13 µg16.25 µg25.49 µglisted usedUS food database (USDA SR Legacy) #171978C

Change the amount to rescale the first column. Nutrients a database doesn't list are missing, not zero.

Hazard rows as the dataset rates them

  • Arsenic, all forms · Context · Context only, not rated: total arsenic is mostly arsenobetaine in bivalves and has no health-based value. The inorganic share is what is rated (next row). · CFIA mercury and metals in fish (2000–2021) · B
  • Cadmium · Limit it: weekly or less · Weekly or less: EFSA's 2009 tolerable weekly intake (TWI) for cadmium is 2.5 µg/kg body weight/week, 175 µg a week for 70 kg. Eaten alone, about 400 g a week of this oyster would reach it. Background is shown, not subtracted: EFSA 2012's adult mean is 1.77 µg/kg body weight/week (range 1.50–2.23), 124 µg a week or 17.7 µg a day. One 125 g serving a day carries 54.7 µg, 309% of the median adult's 17.7 µg a day (245% to 365% across the survey range) and 2.2 times the whole weekly limit if eaten daily. · CFIA mercury and metals in fish (2000–2021) · B
  • Copper · Go easy: within 2 servings of the limit · No cap: EFSA's 2023 acceptable daily intake (ADI) for copper is 0.07 mg/kg body weight/day, 4,900 µg a day at 70 kg, all sources. A 125 g serving of raw eastern oysters carries 3.57 mg on the USDA listing, 73% of the ADI, and about 171 g in one day, eaten alone, would reach it; Health Canada's upper intake level of 10 mg a day would take about 350 g. Copper varies a lot between oysters: CFIA's inspection results averaged a third of the listing (8.72 µg/g, 1.09 mg a serving). · US food database (USDA SR Legacy) · C
  • Dioxins and dioxin-like PCBs · Worth knowing · Flagged: EFSA's 2026 tolerable weekly intake for dioxins and dioxin-like PCBs is 0.6 pg WHO 2022 toxic equivalents/kg body weight/week, 42 pg a week for 70 kg. Eaten alone, about 133 g a week would reach it at the upper bound (0.3147 pg/g) and 309 g at the lower bound (0.136). Mean adult intake of 1.87–5.64 pg/kg body weight/week (18.7–56.4 pg a day) is already above the limit; one daily serving adds 30% (lower bound over the highest background) to 210% (upper bound over the lowest). The data are 4 imported samples from 2017 (Korea 3, China 1), not necessarily the oysters sold in Canada. · CFIA dioxins survey (2014–2019) · B
  • Inorganic arsenic · Not rated yet · Not rated: no safe threshold is set for inorganic arsenic; EFSA's 2024 reference point is a benchmark dose lower limit (BMDL05) of 0.06 µg/kg body weight/day. No Canadian speciation of oysters, and no inorganic-arsenic value from an agency survey, was found, so none is rated. · CFIA mercury and metals in fish (2000–2021) · B
  • Lead · Nothing to watch: doesn’t double average intake · No cap: no safe limit is set for lead (EFSA 2010 benchmark dose lower limit (BMDL01) of 0.5 µg/kg body weight/day), so no grams figure. A 125 g serving carries 4.25 µg, 12% of EFSA 2012's adult mean of 35 µg a day, so one daily serving does not double it. · CFIA mercury and metals in fish (2000–2021) · B
  • Methylmercury · Nothing to watch: under the limit · No cap: EFSA's 2012 tolerable weekly intake (TWI) for methylmercury is 1.3 µg/kg body weight/week as mercury, 91 µg a week. Treating total mercury as methylmercury (conservative for a bivalve), about 2,188 g a week would reach it. That is a floor, since 48 of 57 results were below the detection limit and the mean uses that limit; counting them as zero gives about 30 kg. Mean adult intake is 0.24 µg/kg body weight/week, 18% of the TWI, and a daily 125 g serving carries at most 5.2 µg against a daily allowance of 13 µg. The background range, 0.07–1.08 µg/kg body weight/week, is shown, not subtracted. · CFIA mercury and metals in fish (2000–2021) · B
  • Mollusc allergy · Worth knowing · Flagged for people with a mollusc allergy: Health Canada lists crustaceans and molluscs among the priority food allergens, and oysters are named as molluscs. · Health Canada, Crustaceans and Molluscs - Priority food allergens · A
  • Norovirus · Worth knowing · Flagged for anyone eating raw or lightly cooked oysters: norovirus, with no dose figure. PHAC says lightly cooking oysters is not enough; they need 90 °C for at least 90 seconds. From December 2016 to March 2017, 331 cases of gastrointestinal illness were linked to British Columbia oysters (BC 230, Alberta 42, Ontario 59), with no deaths. A second outbreak, mid-March to mid-April 2018, caused 176 cases (BC 137, Alberta 14, Ontario 25), again no deaths, and closed with the cause of contamination not determined. · PHAC 2017 · A
  • Paralytic shellfish toxins · Not rated yet · Not rated: EFSA's 2009 acute reference dose (ARfD) for paralytic shellfish toxins is 0.5 µg STX equivalents/kg body weight, 30 µg for a 60 kg adult (35 µg at 70 kg) per sitting. No measured retail occurrence was found, so there is no grams figure, and none is computed at a legal limit. EFSA's own illustration: a 400 g portion at the EU limit of 800 µg/kg would give 320 µg, far over the ARfD. In Canada, control works by harvest-area closure. · EFSA 2009 · A
  • Purines and gout · Not rated yet · Not rated for people with gout or hyperuricemia: the only reference is a Japanese dietary recommendation of 400 mg purines a day, seen through Kaneko 2014 rather than an agency document, so no reference is established. Oysters measure 184.5 mg purines per 100 g (HPLC, Kaneko 2014, four purine bases; the species is not stated), so a 125 g serving carries about 231 mg. For scale only, 400 mg would be reached at about 217 g. · Kaneko 2014 · C
  • Raw seafood in pregnancy · Worth knowing · Flagged for pregnancy: Health Canada advises avoiding raw oysters, clams and mussels; shellfish cooked until the shell has opened is the safe alternative. · Health Canada 2025 · A
  • Vibrio · Worth knowing · Flagged for anyone eating raw or undercooked oysters: Vibrio parahaemolyticus is an acute infection risk, with no dose figure; the agency advice is the finding. In 2015 Canada had 82 cases (British Columbia 60, Alberta 19, Saskatchewan 1, Ontario 2), linked mainly to oysters. PHAC names the at-risk groups: pregnant women, people with weakened immune systems, liver disease or low stomach acidity, young children and the elderly. PHAC and Health Canada advise cooking shellfish to an internal temperature of 74 °C (165 °F). The risk does not apply to canned or cooked oysters. · PHAC 2015 · A
  • Zinc · Go easy: can push past the limit · May exceed: Health Canada's tolerable upper intake level (UL) for zinc in adults is 40 mg a day from all sources together. One 125 g serving of raw eastern oysters carries 49.1 mg on the USDA listing, 123% of the UL, and about 102 g in one day, eaten alone, would reach it. Zinc varies a lot between harvests: CFIA's inspection results averaged 314.6 µg/g, 39.3 mg a serving. The UL is a ceiling for long-term daily intake, so the verdict is about habitual daily oyster eating, not an occasional dozen. EFSA's own UL for adults is lower (reported as 25 mg a day). · US food database (USDA SR Legacy) · C

Sources

Body map 2026-10-25.1: each nutrient’s job comes from an agency fact sheet, linked beside it under Good for.

The plain words: “a lot” means one serving (100 g when the food has no serving size) gives at least 20% of the daily amount (the reference intake), “some” at least 10%, “a little” at least 2% (the cut-offs are ours, one set for every page: 20% and 10% are borrowed from the US labelling terms “high” and “good source” and applied to Health Canada’s daily amount, whereas Health Canada’s own shopper rule says 15%; provisional: they may change in a later method version). The daily amount is Health Canada’s Dietary Reference Intake for adults 19–30; where men and women need different amounts we use the higher one (protein: 56 g for men, 46 g for women). The percentage printed under each nutrient is the printed amount as a share of that daily amount, rounded to the nearest whole number, and the word is read from that percentage, so the amount, the percentage and the word always agree. Calcium with a measured absorption is scaled by how well it gets in compared with milk.

The scale: “Nothing to watch” means a serving a day stays under the limit at ordinary amounts; “Go easy” means a serving a day can push past the limit for adults who already take in the most, or fewer than 2 servings reach it; “Limit it” means once a week or less. The dataset’s own rating is under “How we got this”. Provisional: the scale may change in a later method version.

Measured absorption under Good for: grade-A studies in adults that tested this preparation of this food, as a share of the listed amount (the share digested, for protein), quoted once each source has passed our evidence check; animal studies and other variants stay in the table above. Provisional: this screen may change in a later method version.