Mineral cards work like most vitamin cards. Calk adds up a mineral from recorded food over at least seven complete days and compares the daily average with the EFSA reference for your age and sex. The card appears when food alone reaches that reference and, for a mineral with an upper level, when food and logged supplements together stay below it. Below the reference there is no card. The cards are for adults and pause during pregnancy and breastfeeding. The Nutrition Report shows on how many days each mineral had a source.
Absorption can vary with the chemical form, the rest of the meal, health, medication and individual physiology. Blood tests and clinical assessment answer questions that a food log cannot.
Iron Sources#
What Calk calculates. Calk adds up iron from all recorded food: meat, seafood, legumes, tofu, leafy greens, fortified foods. Heme iron from animal foods and non-heme iron from plant and fortified foods absorb differently on average NIH 2024 Hurrell 2010.
What you can do. Pair a plant iron source with a vitamin C source, such as beans with peppers or lentils with tomatoes. Tea, coffee and high-phytate foods can reduce non-heme iron absorption when consumed in the same meal. If deficiency is a concern, have it tested and take clinical advice rather than raising your iron intake blindly.
Calcium Sources#
What Calk calculates. Calk adds up calcium from recorded food: dairy, fortified alternatives, calcium-set tofu, some greens, fish eaten with bones NIH 2024.
What you can do. Check that a calcium source appears regularly. Fortified products vary, so use the current label. Absorption and requirements vary, and a food total cannot assess bone health or replace medical advice.
Magnesium Sources#
What Calk calculates. Calk adds up magnesium from recorded food; nuts, seeds, whole grains, legumes and leafy greens supply most of it. The adult reference differs by sex NIH 2022.
What you can do. Add one familiar source to a repeated meal: seeds on oats, beans in a bowl, nuts with fruit or a whole grain in place of a refined one. Supplements can interact with medicines and can cause adverse effects at high doses.
Zinc Sources#
What Calk calculates. Calk adds up zinc from recorded food: meat, shellfish, dairy, legumes, nuts and seeds. Zinc from plant-heavy diets can be less bioavailable, because phytate binds it NIH 2024.
What you can do. Use a range of food sources. Soaking, sprouting, fermenting and leavening can reduce phytate in some foods. Persistent concern about intake or absorption belongs with a clinician.
Manganese Sources#
What Calk calculates. For manganese the reference is the EFSA adequate intake for adults. Whole grains, nuts, legumes, leafy greens, tea and shellfish such as mussels supply most of it NIH 2021.
What you can do. Keep the whole grains and nuts that supply it. Manganese supplements are rarely needed and can do harm at high doses, especially with liver disease.
Iodine & Selenium Sources#
What Calk calculates. One card covers both minerals, and it appears only when iodine and selenium each reach their reference. Iodine sources include iodized salt, dairy, seafood and seaweed; selenium sources include seafood, meat, eggs, grains, seeds and Brazil nuts NIH 2024 NIH 2024.
The amounts in seaweed and Brazil nuts can vary greatly. Too much iodine or selenium can do harm.
What you can do. Check whether a normal source appears in the recorded pattern. Do not use high-dose supplements to correct a diary estimate, especially when thyroid disease, kidney disease, pregnancy or medication changes the context.