It is true that if you are deficient in a certain mineral you may have an enhanced ability to taste that mineral, and it will taste good.
Iron
lacking some element or characteristic; defective: deficient in taste.
zinc
Insectivorous plants (flycatcher, sundew and slug catcher, to name only three) can grow in nutrient (mineral) deficient soils because they can catch insects and absorb the insect's nutrients.
If we're talking about the American diet, then it's Calcium.
There are many different types of malnutrition, but they can be categorized into several main classes. First is caloric malnutrition, in which there is insufficient overall energy in the diet. Second would be protein/carbohydrate/lipid malnutrition, in which one major class of nutrients is deficient. Third would be vitamin/mineral malnutrition, in which one or more vitamins or minerals are deficient. Fourth would be micronutrient malnutrition, in which certain micronutrients are deficient.
calcium
In a cave, you may be able to taste the dampness or mustiness of the air. Additionally, if there are any mineral formations or water sources within the cave, you may be able to taste the mineral content in the water.
If it wasn't born with orange legs it might be low in copper or some other mineral - a blood test should work out for you which vitamin or mineral that it is deficient in.
She is deficient in Phosphorus. Cows deficient in this mineral eat sand and soil, chew on wood, or even bones from other animals. It might be a good idea to supplement her with phosphorus in her feed or in the mineral mix if other cows like her are showing similar deficiency symptoms.
An area rich in a certain mineral.
juice!!