From the color and shape of the tongue, one can determine which nutrient is deficient and thus learn how to supplement it.
Beefy Tongue: Manifests as a swollen, painful tongue with a bright red surface resembling raw beef. It is particularly sensitive to hot, salty, and acidic foods, and is often accompanied by tongue ulcers, periodontitis, and cheilitis. These are typical symptoms of niacin deficiency. Long-term consumption of corn or sorghum can easily lead to niacin deficiency, and a prolonged deficiency can cause memory loss and Alzheimer's disease. Such individuals should consume more niacin-rich foods, such as: animal liver and kidneys, lean meat, whole grain products, beer, yeast, malt, fish, eggs, nuts, white poultry meat, dates, figs, dried fruits, etc.
Smooth or Mirror-like Tongue: Manifests as an atrophied tongue that has become smaller, with a smooth surface that is pink or red. It is accompanied by a pale complexion, dry and falling hair, brittle nails with longitudinal ridges or even spoon-shaped depressions (koilonychia). These are symptoms of iron deficiency in the body. Middle-aged and elderly vegetarians, as well as patients with atrophic gastritis, chronic diarrhea, or a history of partial gastrectomy, are prone to iron deficiency. Such individuals should consume more animal blood, liver, lean meat, fish, kelp, seaweed, soybeans, spinach, celery, rapeseed, tomatoes, citrus fruits, bayberries, apricots, jujubes, oranges, as well as milk, eggs, soybeans, and soy products.
Expert advice: When consuming peanuts, it should be noted that individuals with yin deficiency and internal heat or excessive internal fire should not eat fried peanuts, as they may exacerbate the heat. Moldy peanuts should be avoided, as they can produce highly carcinogenic aflatoxin. When cooking corn, adding a small amount of baking soda (sodium bicarbonate) can enhance the absorption and utilization of niacin. In plants with iron deficiency, the area between the leaf veins turns yellow, and in severe cases, it may even turn white, with the leaf margins becoming scorched. Iron deficiency in fruits and vegetables not only manifests in the leaves but also affects the quality of the fruit. Therefore, fresh, robust, and good-tasting fruits and vegetables should be selected.