Can You Overdose on Vitamin D

Can You Overdose on Vitamin D

Can You Overdose on Vitamin D ?Vitamin D is a fat-soluble vitamin, and since it is the most deficient element in the body, it is probably the most important.

It is difficult to obtain from food and exposure to sunlight, so supplementation in the form of a food supplement is often necessary. But can vitamin D overdose occur?

These and other related questions will be answered in the following lines.

Vitamin D deficiency

Vitamin D deficiency is most prevalent in modern countries located outside the equatorial and tropical belts, although deficiency does occur there as well.

Logically, since its synthesis is linked to sunlight (UV rays come into contact with the skin and stored 7-dehydrocholesterol is converted to cholecalciferol or vitamin D-3), the populations most affected are those in the northern USA, Scandinavia, the UK and Russia.

  • Vitamin D deficiency statistics have been kept since 1988 using the recommended serum vitamin D concentration of 75 nmol/L as the criterion.

Also at higher risk of deficiency are individuals with various specific medical conditions, pregnant women, and people belonging to races with darker skin color.

A very large proportion of the world’s population is not deficient in vitamin D, but levels are often not within optimal limits.

Obtaining vitamin D when deficiencies or low levels are present is difficult through diet and sun exposure alone, so supplementation is also recommended.

This leads to the question can vitamin D overdose occur.

Vitamin D overdose

Symptoms of vitamin D overdose

The main symptoms of toxicity resulting from vitamin D overdose are:

  • headache, slurred speech;
  • dehydration and constipation;
  • fatigue, irritability;
  • sharp reduction in body weight (and associated reduced appetite);
  • muscle weakness;
  • vomiting;
  • high blood calcium levels.

What vitamin D overdose leads to

Vitamin D is formed in the skin under the influence of the sun’s ultraviolet rays, but there is no danger of toxicity manifestations with prolonged sun exposure.

The physiological action of the fat-soluble vitamin is related to the regulation and metabolism of calcium and phosphorus in the body, i.e., vitamin D ensures the deposition of both calcium and phosphate ions.

Its excess would lead to abnormally high levels of these ions in the blood, resulting in a real danger of bone, kidney and soft tissue damage.

If in doubt, additional vitamin intake should be consulted with a specialist.

Cases of vitamin D overdose are extremely rare, and mainly when an extremely high dose of vitamin D has been taken over a long period of time

There are several recommended doses derived from practice:

  • adult men and women – a minimum effective dose of 2000-3000 IU per day;
  • athletes – 3000-5000 IU daily;
  • patients with osteoporosis and rickets – 5000-10 000 IU;
  • infants and young children – 500-1000 IU daily.

In some cases, high doses of vitamin D can lead to intoxication. A daily intake of more than 20 000 IU is not recommended. However, if you take the vitamin once a week, then the toxic dose exceeds 300,000 IU.

Form of vitamin D intake

There are two main forms of vitamin D that exist on the market:

  • D-2 or ergocalciferol, extracted from plants;
  • D-3 or cholecalciferol, which is derived from animal foods and fish.

Vitamin D-3 is thought to be better absorbed and increases serum vitamin D levels in the body more.

What vitamin D deficiency leads to

Optimal amounts of vitamin D in the body lead to significant improvements in the immune, nervous and bone systems.

Vitamin D deficiency is associated with diseases/conditions such as:

  • Acne, allergic manifestations, asthma;
  • Autoimmune diseases;
  • Autism, Alzheimer’s disease, dementia;
  • Depression;
  • Kidney failure;
  • Arthritis;
  • Osteoporosis;
  • Hypertension;
  • Psoriasis, etc.


Vitamin D is an essential vitamin for a number of body processes and for our optimal health.

Foods from which we can obtain it are scarce – oily fish, red meats, egg yolk.

It is likely that if you do not consume these and/or spend long periods of time indoors without exposure to sunlight, you will need additional intake in the form of a dietary supplement.

Overdosing on vitamin D is possible but extremely difficult.

We recommend consulting a specialist and having your serum vitamin D levels tested before starting supplementation.

Learn more :