Vitamin and Mineral Blood Tests

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Vitamin D Tests

One of the more common vitamin and mineral blood tests is the vitamin D test. A vitamin D deficiency or excess can lead to problems such as bone malformation, bone weakness and improper calcium metabolism. Monitoring vitamin D levels is one way to detect diseases that cause improper fat absorption, such as Crohn’s disease.

There are two types of vitamin D: 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D. A blood test to measure 25-hydroxyvitamin D is ordered when the calcium levels are low. Low levels of 25-hydroxyvitamin D has several causes including lack of exposure to sunlight and improper vitamin D absorption.

A blood test to measure 1,25-dihydroxyvitamin D is ordered when there is an excess of calcium in the blood. Low levels of 1,25-dihydroxyvitamin D in the blood indicates early kidney failure. High levels of the vitamin indicate excess production of the parathyroid hormone or some form of lymphoma.

Vitamin B12 Test

Doctors usually check the level of vitamin B12 in the blood to help diagnosis a certain type of anemia called macrocytic anemia. It is also checked when individuals have signs of malnutrition or nerve damage. When the blood is tested for vitamin B12, it is usually tested for folates as well.

A low level of vitamin B12 indicates anemia or neuropathy. A high level of vitamin B12 is seen in individuals with leukemia or liver dysfunction.

Vitamin K Test

There are three types of vitamin K: Vitamin K1 (phylloquinone), Vitamin K2 (menaquinone) and Vitamin K3 (menadione). The main causes of vitamin K deficiency include dietary deficiency, malabsorption, and drug interaction. Usually, a vitamin K deficiency is suspected when an individual bleeds excessively from wounds or is easily bruised.

The vitamin K deficiency test involves the prothrombin time test, which is used to determine how well the blood is clotting. A sample of blood is drawn and tested to see how long it takes to clot. If it is longer than normal, the individual is given an injection of vitamin K. Another blood sample is drawn and tested. If the blood clots quicker, then the individual probably has a vitamin K deficiency.

Calcium Test

Similar to other vitamin and mineral blood tests, the calcium test checks the blood to see if there is an excess or deficiency in the mineral calcium. Calcium is found in the teeth and is an essential element for muscle contraction and nerve function. The calcium test is usually part of a broader set of tests called the comprehensive metabolic panel or the basic metabolic panel

Hypercalcemia is a condition where there is too much calcium in the blood. It is usually caused by an overactive parathyroid. Hypocalcemia is a condition where the calcium level in the blood is low. This is usually caused by a low level of albumin in the blood.

Iron Tests

There are several tests that measure how iron is utilized in the body. The serum iron test measures the amount of iron in the blood, while the total iron binding capacity (TIBC) measures the proteins in the blood that are available to bind with iron. Another test that deals with iron is the serum ferritin test, which measures the total amount of stored iron.

A low blood iron level can cause anemia, while a high blood iron level can cause hemochromatosis, which leads to organ failure. Signs of low iron levels include dizziness and weakness. An excess amount of iron causes joint pain, abdominal pain, and heart problems.


1. Vitamin D: The Test. Lab Tests Online June 18, 2010