Calk estimates vitamins from recorded food and compares the average with dietary reference values. This can reveal a narrow food pattern or a missing source. It cannot measure blood levels, absorption, sunlight exposure or individual medical needs.
Vitamin A Sources#
What Calk calculates. Calk combines preformed vitamin A from foods such as liver, eggs and dairy with provitamin A carotenoids from orange and dark-green produce, using retinol activity equivalents NIH 2023.
What you can do. Add a familiar source if the recorded pattern is low. Liver and some supplements contain very high preformed vitamin A; pregnancy and medical context require particular care.
Vitamin C Sources#
What Calk calculates. Calk estimates vitamin C from fruit and vegetables such as peppers, citrus, berries, kiwi, broccoli and potatoes NIH 2021.
Cooking and storage can change the amount, so the database value is an estimate. Use the result to check whether vitamin-C-rich foods appear regularly.
Vitamin D Sources#
What Calk calculates. Calk counts vitamin D in recorded fatty fish, egg yolks, fortified products and some mushrooms NIH 2023.
The food diary cannot see vitamin D made in the skin or interpret a blood test. If vitamin D status is the question, that calls for a blood test and clinical guidance.
Vitamin E Sources#
What Calk calculates. Calk estimates vitamin E from nuts, seeds, plant oils, avocado and leafy greens NIH 2021.
What you can do. Look for a regular food source. Food and high-dose antioxidant supplements are different questions.
Vitamin K Balance#
What Calk calculates. Calk records K1 and K2 separately where the food data has them, and the vitamin-K card itself reads K1, which the food tables cover most completely. K1 is common in leafy greens and other vegetables; K2 occurs in some fermented foods, dairy and animal foods NIH 2021.
Food-composition data for K2 is less complete than for many common vitamins. People taking warfarin or similar medication should follow clinical advice on keeping vitamin K steady, and should not change their vitamin K intake on the basis of an app result.
Vitamin B12 Sources#
What Calk calculates. Calk estimates B12 from animal foods and fortified products. Unfortified plant foods are not reliable B12 sources NIH 2024.
What you can do. If animal foods are limited, check labels on fortified foods and discuss supplementation when appropriate. Absorption can also be reduced by age, gastrointestinal conditions and some medicines, which the diary cannot determine.
Folate Sources#
What Calk calculates. Calk uses dietary folate equivalents to combine natural folate from legumes, greens, citrus and other foods with folic acid from fortified foods NIH 2022.
In pregnancy, follow the medical guidance rather than this food estimate. People who could become pregnant may need folic acid in addition to food according to local medical recommendations.
Choline Sources#
What Calk calculates. Calk estimates choline from eggs, meat, fish, dairy, soybeans, legumes and cruciferous vegetables NIH 2022.
What you can do. Add a source that fits the existing diet. Requirements vary, including during pregnancy and breastfeeding. The app reports food coverage.
Lutein & Zeaxanthin Sources#
What Calk calculates. Calk estimates lutein and zeaxanthin from foods such as dark leafy greens, corn, egg yolks and orange peppers. These carotenoids accumulate in the retina, but no general dietary reference intake has been established.
AREDS2 studied a specific supplement formulation in people with age-related macular degeneration. Its result belongs to that formulation and that group Age-Related 2013.
Fat-Soluble Nutrient Context#
What Calk calculates. Calk checks whether a meal containing carotenoid-rich produce or vitamins A, D, E and K also contains a source of fat. Dietary fat can increase carotenoid absorption, but the effect varies by nutrient, food and person Brown 2004.
What you can do. If a vegetable-heavy meal contains virtually no fat, add an ordinary amount of oil, nuts, seeds, egg, dairy or avocado if it suits the meal. More fat is not automatically more absorption.
Micronutrient Coverage#
What Calk calculates. Calk checks which vitamins and minerals have a source in the diary at all, and on how many complete log days each one appears. It then names the foods behind the well-covered and the thin areas. This is a coverage question.
The result is only as complete as the diary and ingredient data. It cannot confirm that the body absorbed the nutrients or that a low value caused a symptom.
Spermidine Sources#
What Calk calculates. Calk tracks spermidine estimates for foods where specialist source data is available, including wheat germ, mushrooms, soy foods, legumes and some aged cheeses Eisenberg 2016.
This is a food-source and variety view: which foods in the diary carry spermidine, and how often. Autophagy and longevity are well beyond what a diary can show.