Vitamin D3

Too much Vitamin D?

Vitamin D is one of the most important vitamins. But the majority of commercially available vitamin D products contain far too little vitamin D. 10 or 20 mcg (400 or 800 IU) per day is very little.

Moreover, excess vitamin D is extremely rare, even when taken in doses much higher than the maximum allowable dose of, currently, 100 mcg.

Vitamin D production by sunlight

For comparison, on a sunny summer day in July/August, between 11 a.m. and 3 p.m., our bodies quickly make more than 250 mcg per day. Adults and adolescents are therefore best to opt for a slightly higher-dose vitamin D such as Jarrow's 2500 IU (62.5 mcg) or an easily dosed liquid vitamin D such as Thorne's Vitamin D3 liquid.

Vitamin D is needed for our immune system, strong bones, muscles, teeth and the cell division process. It is best to choose the animal form "vitamin D3. This animal form usually comes from lanolin (wool fat) and is therefore suitable for vegetarians but not for vegans.

Products containing both vitamin D and vitamin K can be found on the Vitamin K2 page.

Vitamin D is good for:

• Immune-system
• Bones
• Muscles
• Teeth
• Cell division process

Vitamin D deficiency

Vitamin D deficiency can cause serious problems, especially for the bones. For everyone, but especially children and the elderly.

Whether vitamin D deficiency the case varied years ago, depending on who you asked. But in recent years, in Europe for vitamin D (25-hydroxyvitamin D) consensus has emerged on serum values for vitamin D: a minimum value of 50 nmol/L and a target value of 75 nmol/L.

Vitamin D deficiency symptoms

Some possible symptoms of vitamin D deficiency are unexplained muscle problems or muscle weakness. High-risk groups include the elderly, people with dark skin tone, the chronically ill, "indoor sitters," frequent users of sunscreen and people who are severely overweight.

Because virtually everyone falls into one of the high-risk groups, Thuisarts.nl advises the majority of the Dutch population to take a vitamin D pill every day.

Vitamin D side effects

Contrary to what part of the medical community want us to believe believe, vitamin D is not dangerous. It is a very safe substance. The number of people in the Netherlands who have experienced problems from excessive vitamin D intake in recent years is can be counted on the fingers of one hand.

In a few cases, the cause was "bad" vitamin D supplements that contained an extremely much higher dose of vitamin D than was mentioned on the label.Another case involved vitamin D medication, not a vitamin D supplement.

Dutch vitamin D expert Frits Muskiet even argues that vitamin D is even safer than water: eight glasses of water a day is fine for an adult,but if you drink ten times that amount of water in one day you will suffer water intoxication, which can be fatal.

While taking 20 times the daily dose of vitamin D at one time is perfectly safe.

Cholecalciferol

Vitamin D3 (cholecalciferol) is the most effective form of vitamin D. It increases calcium absorption in the bones and has a positive impact on the immune system.

Why Vitamin D?

As expected, RDAs and maximum allowable doses for vitamin D continue to rise.

This sunshine vitamin is formed in the skin under the influence of ultraviolet light. But this happens only when the sun is high enough in the sky, which is only the case in the summer months and then only between about 11 and 16 hours. Outside this period, the amount of UV-B is too low for sufficient vitamin D production in our skin. In the winter, no vitamin D is produced in the skin at all and we are therefore dependent on sufficient intake with the diet.

Vitamin D in Multivitamins

But my multivitamin already contains vitamin D. Then I don't need to take separate vitamin D in addition, do I?

Some truly good multivitamins excepted (such as the Thorne Advanced Nutrients), there are virtually no multis that contain enough of this essential vitamin. And by sufficient, we don't mean the RDA/RI, but the optimal amount, which is significantly higher.

Explanation Vitamin D dosages

The dosage of vitamin D3 products is sometimes a bit confusing. Some products use IE or IU (International Units/Units) in their naming, while others state the dosage in micrograms (mcg). The table below shows the relationship between these 2 dosage methods:

People who buy Vitamin D3 also use:

• Nicotinamide Riboside
• Vitamin K2 MK-7
• Vitamins
• Multivitamin
• Lactoferrin
• Resveratrol

Written by: Wouter Olthof
Reviewed by: Liesbeth Thoen

Updated: December 24, 2023