Vitamine D Home Test
October 15, 2021

Why Do We Need Vitamin D?

All HOMED-IQ content is reviewed by medical specialists

Vitamin D deficiency is one of the most common vitamin deficiencies, with recent studies estimating that approximately 40% of Europeans are deficient in Vitamin D and nearly 13% are severely deficient (Amrein et al., 2020). Since symptoms of Vitamin D deficiency are not always obvious, low levels can often go unnoticed. However, Vitamin D plays an important role in overall health and is important. Its functions include supporting muscle function, bone health, and the immune system. This is why it is important to understand how this vitamin functions in our body and how to achieve the optimal amount.

What is Vitamin D?

Vitamin D is not only a nutrient we consume, but also a hormone our bodies produce as a result of food intake. It’s a fat-soluble vitamin required to keep our muscles, teeth, and bones healthy. Vitamin D is also known as the “sunshine vitamin” and is present in three forms: Vitamin D-1, D-2, and D-3.

What Roles does Vitamin D perform in your body?

Vitamin D is essential for the normal growth and development of our body and the maintenance of health. Some of the well-studied benefits of Vitamin D are:

  • Maintaining strong Bones: Vitamin D regulates the absorption of calcium and phosphorus in the body, which aids in building bones. A deficiency of Vitamin D can lead to osteoporosis (a condition of having fragile bones) or osteomalacia (condition of having soft bones).
  • Building stronger muscles: Vitamin D helps in building stronger muscles. It increases muscle mass and enhances muscular functions.
  • Boosting immunity: Vitamin D plays a major role in fighting bacterial and viral infections. Additionally, several studies have found its significant involvement in fighting diseases like acute respiratory infections and pneumonia.

Source: Mayo Clinic, 2021

Why is it important to obtain the right amount of Vitamin D?

A healthy amount of Vitamin D is essential for the body to function properly, as too much, or too little Vitamin D can lead to adverse health effects. But how much Vitamin D do we need?
Assuming minimal sun exposure, the Recommended Dietary Allowance (RDA) for vitamin D on a daily basis is:

  • The RDA for adults of 19-70 years is 600 IU/day, for both men and women. For people >70 years of age, the recommended amount of Vitamin D is 800 IU/day.
  • The safe upper limit of Vitamin D is 4000 IU/day for adults and children of 9+ age.

Intake of Vitamin D below or above the recommended limits can lead to poor health (Harvard Public Health, 2022)

Deficiency of Vitamin D

Vitamin deficiency can occur for multiple reasons, including poor absorption in the body, higher metabolic needs, or lack of Vitamin D in the diet. People who follow a vegan diet or are lactose intolerant are more at risk of a deficiency of vitamin D.
Some of the conditions resulting due to Vitamin D deficiency include:

  • Rickets
  • Osteomalacia

Source: Mayo Clinic, 2021

Excess of Vitamin D or Vitamin D Toxicity

Too much of a good thing does exist. Excessive Vitamin D uptake results in a condition called Vitamin D toxicity. This cannot occur from sun exposure- only from the excessive intake of Vitamin D supplements. This is because after adequate production of Vitamin D occurs in our bodies, our skin prevents the formation of additional Vitamin D3.
Vitamin D toxicity leads to health issues such as:

  • Abnormal heartbeat
  • Increased levels of calcium, which can cause damage to the heart and kidneys
  • Weight loss

Source: Zeratsky, 2022

What Are the Best Sources of Vitamin D?

Sunlight is the major natural source of Vitamin D. Our skin has the capability to synthesize Vitamin D3 when it comes in contact with UVB light rays. This is why in regions of the world with low amounts of sunlight, Vitamin D deficiency is more common. Vitamin D can also be obtained through a variety of natural or fortified food sources, which include:

  • Fish such as salmon, herring, mackerel, and sardines.
  • Red meat, liver, and egg yolk.
  • Shrimp and tuna.
  • Cereal and orange juice.
  • Cheese and mushrooms.

For more tips on how to boost your vitamin D levels, read our blog.

How to know if you are Vitamin D deficient

While Vitamin D is essential to our body’s functioning, it can be difficult to know when you are deficient or not. This is because there are no specific symptoms for Vitamin D deficiency, and they can be confused for other health conditions. Symptoms include:

  • Fatigue
  • Muscle weakness/pain
  • Mood changes or depression
  • Bone pain

Source: Cleveland Clinic, 2022

If you are curious about your Vitamin D levels or experience any of the above symptoms, testing can be performed by visiting your GP or testing from home with Homed-IQ’s Vitamin D Test.
The Homed-IQ’s Vitamin D Test measures the (25-hydroxy vitamin D) in your blood sample and provides you fast, accurate results. The test provides laboratory certified results without needing to visit a doctor’s office, and only requires a finger prick rather than a blood draw from your vein. It couldn’t be easier!
For more information on Vitamin D testing, check out Homed-IQ’s Vitamin D test.


Amrein, K., Scherkl, M., Hoffmann, M., Neuwersch-Sommeregger, S., Köstenberger, M., Tmava Berisha, A., Martucci, G., Pilz, S., & Malle, O. (2020). Vitamin D deficiency 2.0: an update on the current status worldwide. European Journal of Clinical Nutrition, 74(11), 1498–1513.

Vitamin D. (2021, February 9). Mayo Clinic.

Vitamin D. (2022, November 14). Havard Public Health.

Vitamin D Deficiency: Causes, Symptoms & Treatment. (n.d.). Cleveland Clinic.

Zeratsky, K. (2022, March 22). Vitamin D toxicity: What if you get too much? Mayo Clinic.

About the author

Lauren Dobischok

Lauren is a health scientist and science communicator living in the Netherlands. With a background in epidemiology, her goal is to create accurate scientific content that is easy to understand and empowers people to make informed decisions. Her favourite topics to discuss are public health, infectious diseases, and dispelling myths and misconceptions about health topics with research. Coming from Canada, Lauren prefers to spend her free time learning Dutch and exploring the interesting sights this small country has to offer!