An AST blood test measures aspartate aminotransferase, an enzyme found in the liver, muscles, heart, and other tissues. Learn what AST results can mean, how to prepare, what can affect the test, and when follow-up testing may be needed.
A parathyroid hormone blood test helps explain abnormal calcium levels and can point toward primary hyperparathyroidism, secondary hyperparathyroidism, hypoparathyroidism, kidney-related mineral imbalance, or other causes. Learn how the test works, how to prepare, and how to interpret PTH with calcium and related labs.
A copper blood test measures copper in serum or plasma to help evaluate copper deficiency, excess copper exposure, nutrition support, and possible copper metabolism disorders such as Wilson disease. Learn how the test works, how to prepare, what results may mean, and when related tests matter.
A zinc blood test measures zinc in serum or plasma to help evaluate suspected deficiency, excess exposure, malabsorption, supplementation, and nutrition support. Learn how to prepare, what results can mean, and what to ask next.
A magnesium blood test measures magnesium in the liquid part of your blood to help evaluate electrolyte balance, kidney function, medication effects, and causes of symptoms such as cramps, weakness, irregular heartbeat, or abnormal calcium and potassium levels.
A vitamin D blood test usually measures 25-hydroxyvitamin D, the best marker of vitamin D stores. Learn when testing is useful, how to prepare, how to interpret common result ranges, what can affect accuracy, and what to ask before paying out of pocket.
A folate blood test measures vitamin B9 in your blood and is commonly used to evaluate possible folate deficiency, macrocytic anemia, pregnancy-related nutrient needs, and malabsorption concerns.
A transferrin blood test helps evaluate how your body transports iron. Learn what high, low, and normal transferrin results may mean, how to prepare, and how it compares with ferritin, TIBC, and transferrin saturation.
An iron and TIBC blood test helps evaluate how much iron is circulating in your blood and how much iron-carrying capacity is available. Learn what the results can mean, how to prepare, and what to ask your clinician next.
A ferritin blood test measures stored iron. Learn what low and high ferritin can mean, how to prepare, how results are interpreted with other iron tests, and what to ask next.
