Vitamin D, B12 & Calcium

The Serum Calcium test measures the levels of calcium in the body. Calcium is the most abundant mineral in the body; most of it is present in the bones and teeth, and the remaining portion (around 1%) is found in the blood. It is usually present in two forms in blood in about equal amounts: "bound calcium," which is attached to proteins in the blood, and "free calcium or ionized calcium," which is not attached to any protein. 

The Serum Calcium test cannot be used to check for lack of calcium in your diet or osteoporosis (loss of calcium from bones) as the body can have normal calcium levels even in dietary calcium deficiency. Moreover, the body can normalize mild calcium deficiency by releasing the calcium stored in bones.

The Vitamin B12 test measures your vitamin B12 levels. Vitamin B12 is essential for various health aspects, such as maintaining a healthy nervous system, making red blood cells, and creating the genetic material of our cells. Low vitamin B12 levels are more likely to occur in older adults, children, vegans, vegetarians, people with diabetes, individuals who underwent gastric bypass surgery, women who are breastfeeding, and in conditions that impact absorption of this vitamin, like Crohn’s disease. Higher vitamin B12 levels seen in pateint on vitamin suplement does not need treatment as excessive vitamin B12 is usually removed through the urine. However, some conditions, such as liver diseases and myeloproliferative disorders, can cause an increase in vitamin B12 levels, thereby affecting blood cell production.

The Vitamin D (25-Hydroxy) test measures the levels of vitamin D in the body. It is an essential nutrient that can be synthesized in the body upon healthy exposure to sunlight or absorbed from dietary sources. It majorly exists in two forms: Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Vitamin D2 is present in plants, such as yeast or mushrooms, and is available as a supplement in fortified foods, and vitamin D3 is found in foods like cheese, green vegetables, mushrooms, egg yolks, and fatty fish.

Both forms of vitamin D (D2 and D3) need to undergo some chemical changes before being available for use in the body. These chemical changes take place in the liver or kidneys.The levels of 25-hydroxy Vitamin D in blood is considered the best parameter to assess vitamin D status of the body. A Vitamin D (25-Hydroxy) measures the level of Total 25-OH vitamin D (D2+D3) , but it does not differentiate between the two forms as it is the major form of vitamin D that circulates in the blood.