• £45.00

Vitamin D Testing D2 and D3 in dried blood spots  25OH Total Blood

    • Detects deficiencies in Vitamin D (independently monitoring both Vitamin D2 and D3 status by LC-MS/MS) as a potential cause of health problems ranging from osteoporosis to cardiovascular disease.
    • A simple, convenient and accurate test for screening Vitamin D levels.
    • Vitamin D testing in dried blood spots: A few drops of blood from a quick and nearly painless nick of the finger are placed on a filter paper to dry.  This can be performed easily either at a health practitioner's office or the convenience of home.  
    • After Laboratory receives your sample you will receive your test result in 7 days. 
    • With this innovative blood spot test, there is no more wasted time and resources going to a lab for a painful blood draw.
    • ZRT Laboratory: Established in 1998 and now celebrating 15 years of success, ZRT is a CLIA certified diagnostic laboratory and the leader in hormone and wellness testing. We provide accurate and meaningful test results that assist healthcare providers in making informed treatment decisions. 
    • Customers are responsible for shipment to laboratory(*).
    • No additional Cost and Tax.

    Vitamin D in Blood Spot

    Vitamin D Deficiency – A Real Problem

    Most people are familiar with vitamin D’s role in preventing rickets in children and in helping the body absorb calcium from the diet.

    Recently, research has shown that vitamin D is important in protecting the body from a wide range of diseases. Disorders linked with vitamin D deficiency include:

    • Stroke,
    • Flu,
    • Cardiovascular disease,
    • Osteoporosis,
    • Osteomalacia,
    • Several forms of cancer, 
    • Some autoimmune diseases such as multiple Sclerosis, 
    • Rheumatoid Arthritis, 
    • Type I Diabetes & Type II Diabetes,
    • Breast and Colon Cancer (linked to Vitamin D Deficiency),
    • Depression and even schizophrenia.

    Vitamin D is actually a prohormone and not technically a vitamin: a vitamin is defined as a substance that is not made naturally by the body but must be supplied in the diet to maintain life processes. But in fact, we make most of our vitamin D by the action of ultraviolet light (sunlight) on the vitamin D originator that is found in our skin. We only get very small amounts of vitamin D from our diet, although increasingly it is added to foods eaten by children, in an attempt to prevent rickets in the population.

    Cause of Vitamin D Deficiency

    A major cause of deficiency is not getting enough sun.

    This happens because people don’t spend much time outdoors, women in particular often have much of their skin area covered for cultural reasons, and the use of sunscreen also blocks the formation of vitamin D in the skin.

    Why Vitamin D Deficiency Test?

    Testing for vitamin D is therefore an important screening test, especially if you spend much of your time indoors, or live in a colder climate. This blood spot test measures both the natural form of Vitamin D (D3) as well as D2, the form that is used in many supplements. So testing can be used to monitor vitamin D supplementation to ensure you are getting the right amount for optimum health.

    Who is at Risk?

    The Elderly

    Amounts of the vitamin D originator in the skin decrease with age, therefore elderly people are particularly prone to deficiency, and living in rest homes or becoming home-bound can limit exposure to sunshine. Muscle weakness and osteoporosis associated with vitamin D deficiency make the elderly more susceptible to falling and fracture risk and studies show that vitamin D supplementation may decrease the risk of fractures.

    Dark-Skinned People

    Because people with darker skin have higher levels of melanin which can block the action of sunlight on vitamin D originators, they may require much longer sunlight exposure than people who are fair skinned.

    People with Limited Sunlight Exposure

    People living at northern latitudes or who have limited sunlight exposure because of their working environment or cultural dress rules may have low vitamin D levels.

    Musculoskeletal Pain Sufferers

    People with symptoms of hypothyroidism, non-specific musculoskeletal pain, chronic low back pain, or fibromyalgia are frequently found to have low vitamin D levels and show clinical improvement after supplementation. Vitamin D screening is strongly recommended in people with muscle and joint pain.

    Overweight or Obese People

    Vitamin D can be locked up in the fat stores of obese people, who have been found to have lower levels of circulating vitamin D and are at risk of deficiency.

    Breast-Fed Infants and Children with Limited Sunlight Exposure

    All children require adequate circulating vitamin D to prevent rickets. Dark-skinned children and those who spend much of the day inside day-care centres are at risk of deficiency, and breast-fed children often receive inadequate amounts of vitamin D, particularly when their mothers are deficient. Giving vitamin D supplements to the nursing mother or the use of cod liver oil or other vitamin D supplements in infants and children can reduce the risk of developing type I diabetes in childhood.

    Vitamin D screening has been recommended as a routine part of the annual physical examination. Deficiency does not have obvious symptoms, but increases your risk for more serious diseases.

    Advantages of a Simple Blood Spot Test

    Whole blood is collected with a simple nick of the finger using the lancet provided in the collection kit. Blood drops are dropped on the filter card provided and allowed to dry. The lab measures the vitamin D in the dried blood spots, which correlate closely with conventional blood tests done in serum.

    People have chosen this blood spot test because:

    • It is less expensive and more convenient than going to a phlebotomist or clinic for a blood draw, and samples are simply mailed in for analysis requiring no special storage conditions

    • It is suitable for babies and children, since heel stick is already used in routine neonatal screening and it’s easy to collect a few extra drops of blood at the same time

    • Collection is minimally-invasive and nearly painless

    Clinical Utility

    Blood spot testing of Vitamin D can help your doctor:

    • Identify vitamin D deficiency as a potential cause of health problems – levels below 20 ng/mL indicate deficiency, while levels below 32 ng/mL are “low”; optimal levels are 32-100 ng/mL (research is on-going to establish definitive recommendations)

    • Recommend the right dose of vitamin D as a supplement and monitor your D levels during

    Supplementation to ensure you have adequate levels without overdosing – toxicity may be expected at levels >150 ng/mL

    • Recommend appropriate ways to safely increase sunlight exposure and modify your diet to include more vitamin D-containing foods and/or supplements

    • Track treatment progress with follow-up testing

    DISCLAIMER: Laboratory is a testing facility only, and does not diagnose, treat, or recommend treatment for medical conditions.


    The specimen collection process is quick, easy and virtually painless. Using the special finger lancet, which is included in the Vitamin D Test Blood Collection Kit, a couple of drops of blood are taken from a nick of a finger and deposited into a special collection card. The card is then sent to a Certified Laboratory for analysis.

    Once Laboratory has received your dried blood spot sample, your results will be available in about a week. As you continue to monitor your Vitamin D levels, Laboratory will generate a "history" test report with your newest test results compared with previous tests. This will enable your health care provider to recommend the right dose of supplementation, if necessary, and then track your treatment progress. 

     Shipping To Laboratory: Customers are responsible for shipping their sample to ZRT Laboratory based in USA. Shipping usually cost between £5-£8 if the customer send via Royal Mail (Post Office) and it usually takes 3-5 working days to reach the Laboratory. Your sample usually remain fresh up to 30 days. 

    How to Use 

    blood spot use introduction



    Back to the top