Final answer:
Vitamin D can lead to toxicity by raising blood calcium levels, causing hypercalcemia. It is a fat-soluble vitamin, and its excess gets stored in body fat, which can lead to toxic levels. One should adhere to the Tolerable Upper Intake Levels to avoid such toxicity.
Step-by-step explanation:
The vitamin that can cause toxicity by raising the concentration of calcium in the blood is vitamin D. When vitamin D is activated in the body, it increases the absorption of calcium in the digestive tract and helps in maintaining normal serum concentrations of calcium and phosphate. If too much vitamin D is consumed, it can lead to hypercalcemia—a condition where calcium levels in the blood become too high, resulting in health issues such as lethargy, constipation, and confusion, and in severe cases, coma.
Vitamin D toxicity is particularly concerning because unlike water-soluble vitamins that are excreted in urine, vitamin D is fat-soluble, meaning your body stores excess amounts in body fat, which can lead to toxic levels accumulating over time. Consequently, it's essential to adhere to the Tolerable Upper Intake Levels (UL) for vitamin D to avoid toxicity. Common sources of vitamin D include sunlight, certain foods, and dietary supplements.