Comparing Vitamin D3 Supplements
Quick and concise comparison of Vitamin D3 from quality certified brands.
Grouped by potency
Ordered by cost per microgram
Deciders easily comparable
Benefits of Vitamin D
According to Examine’s excellent Human Effect Matrix, the benefits of Vitamin D include:
- Improved immunity especially in regards to upper respiratory tract infections.
- Reducing the severity of COVID-19.
- Improving bone health.
- Can reduce the risk of diabetes and multiple sclerosis.
- A reduction in mortality from all causes.
The above benefits are likely only relevant if the amount of Vitamin D in the blood is low.
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How is Vitamin D absorbed?
Because it is a fat soluble vitamin, when taken orally, Vitamin D should be consumed with food that contains fat. Liposomal Vitamin D contains fat and can be absorbed without food.
Vitamin D is synthesized in the skin from ultra violet light in the form of UVB rays from the sun. Therefore, people with limited exposure to the sun may need more Vitamin D than they get from their diet.
The sun creates Vitamin D3 from the skin. This is either stored in fat cells or converted by the liver and then kidneys to calcitrol. Calcitrol is the form of Vitamin D that the human body uses. The liver and kidneys can also convert Vitamin D2 into calcitrol.
Vitamin Inspector has chosen to compare Vitamin D3 as it has been shown to be more effective than Vitamin D2 in raising levels of Vitamin D in the blood.
Read more about Vitamin D at the Linus Pauling Institute’s Micronutrient Information Center.
Safety and Potency
According to the US Government’s National Institute of Health (NIH), the recommended daily allowance (RDA) for Vitamin D is 15 mcg for both male and female humans in the age ranges of 1 to 69 years. For those over 70 years the RDA is 20 mcg.
The tolerable upper intake is 100 mcg per day for people over the age of 9 years. And less for those under 9 years.
This data is correct as at 30 July 2022.
Comparison of Vitamin D3 25 mcg (1,000 IU)
as Vitamin D3
(as D3, Cholecalciferol)
Vitamin D3 (cholecalciferol) (from lichen) (whole)
National Sanitation Foundation (NSF) are an independent organisation that conduct supplement quality testing and also audit plant and processes of supplement manufacturers for adherence to good manufacturing standards.
Liposomal Vitamin D: Because Vitamin D is fat soluble, it should usually be taken with food. Liposomal Vitamin D contains fat which means it can be consumed on an empty stomach.
Safety and Potency above for more info.Vitamin D safety: The RDA for Vitamin D for adults under 70 is 15 mcg per day. The upper safe limit to consume on a continual basis is 100 mcg per day for adults. See