Vitamin D (25-Hydroxy) & Vitamin B12

A 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 are uncommon 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.

A 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 liver converts vitamin D to 25-hydroxyvitamin D (25-OH vitamin D). A Vitamin D (25-Hydroxy) test measures the level of this 25-OH vitamin D as it is the primary form of vitamin D that circulates in the blood.