Vitamin D, B12 & Calcium

The Serum Calcium test measures the calcium level in your blood. Most of your body’s calcium (about 99%) is stored in bones and teeth to keep them strong. The rest (1%) circulates in the blood and helps your muscles move, nerves work, blood to clot, and heart to keep a steady rhythm.

Calcium in blood comes in two forms:

• Bound calcium, attached to proteins like albumin
• Ionized (free) calcium, which is active and helps many body functions

This test measures total calcium (both bound and ionized). This test cannot show if you have enough calcium in your diet. It also cannot detect bone diseases like osteoporosis. The body keeps blood calcium levels steady. It does this by taking calcium from bones during mild shortages.

The Vitamin B12 measures the amount of vitamin B12 in your blood. Vitamin B12 is important for a healthy nervous system, making red blood cells, and creating DNA in your cells. Low B12 levels are common in older adults, children, vegans or vegetarians, people with diabetes, those who had gastric bypass surgery, breastfeeding women, and people with conditions like Crohn’s disease that affect vitamin absorption. High B12 levels can occur in liver diseases, certain blood disorders, or from taking vitamin supplements. Usually, high levels from supplements are not harmful, as extra B12 is removed through urine.

The Vitamin D (25-Hydroxy) test measures the levels of vitamin D in the body. Vitamin D is an essential nutrient that can be synthesized in the body upon healthy exposure to sunlight or absorbed from dietary sources. It 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. Vitamin D3 is found in foods like cheese, green vegetables, mushrooms, egg yolks, and fatty fish.

Both forms of vitamin D need to be converted in the liver and kidneys before the body can use them effectively. This test shows the total level of vitamin D (D2 + D3) circulating in the body and guides your doctor in recommending the right treatment or lifestyle changes if needed.