Don't get enough sun in winter and still want to strengthen your immune system? Then high-dose vitamin D could be just the thing for you and your health. If you want to learn more about the intake, the scientific background and the necessary criteria for buying high-dose vitamin D, then you have come to the right place. We are pleased that you have found your way to our large high-dose vitamin D test 2020. You will get all the information you need about vitamin D and learn how and when to use it.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The Best High-Dose Vitamin D: Our Picks
- 4 Buying and evaluation criteria for high-dose vitamin D
- 5 Guide: Frequently asked questions about high-dose vitamin D answered in detail
- 5.1 What is high-dose vitamin D and how does it work?
- 5.2 When and for whom is it useful to take high-dose vitamin D?
- 5.3 What are the possible side effects of taking high doses of vitamin D?
- 5.4 How much do high-dose vitamin D products cost?
- 5.5 What types of high-dose vitamin D are available?
- 5.6 What alternatives are there to high-dose vitamin D?
- Vitamin D can be synthesised in the human skin itself under the influence of UV-B radiation. If vitamin D supplements are resorted to, they should contain oil, as vitamin D is fat-soluble.
- High-dose vitamin D is available in the form of drops or capsules. When choosing a supplement, the active ingredient vitamin D3 should be chosen, as it has a higher bioavailability than vitamin D2.
- The dosage of vitamin D depends on body weight, age and season. Dosages of 200 IU to 20,000 IU of vitamin D are available.
The Best High-Dose Vitamin D: Our Picks
Buying and evaluation criteria for high-dose vitamin D
When buying high-dose vitamin D, you can look at various aspects, such as:
By making the right choice for you, you can save money and also ensure that you don't give your body anything it doesn't need. Therefore, always look for high quality and ask to see the manufacturer's certificates if necessary.
The dosage of vitamin D should depend on body weight, age, season and blood values. Dosages of 200 IU to 20,000 IU vitamin D are available. Before starting a therapy, a blood test should be carried out by a doctor. The doctor will then prescribe the right therapy (3). For blood levels of less than 30 ng/ml vitamin D, it is usually recommended to start an initial therapy of 5000 to 20,000 IU vitamin D per day. When choosing a maintenance dose to meet daily vitamin D requirements, 3000-4000 IU per day is recommended. In summer and during pregnancy, a low dose of 400 to 2500 IU should be maintained (3).
When choosing a high-dose vitamin D supplement, make sure that the active ingredient is vitamin D3 or vitamin D3 vegan. This has a significantly higher bioavailability and thus effectiveness than vitamin D2 (2). While non-vegan vitamin D3 is made from sheep's wool, the vegan version comes from lichen.
When taking vitamin D supplements, make sure that they are free of additives. Some preparations contain additives that are suspected of causing side effects. They also increase the risk of contamination. Magnesium stearate, stearic acid, iron oxide, titanium oxide, aspartame and xylitol should be avoided for this reason (10). In addition, harmful substances from the packaging can also dissolve in the oil. Another problem is that manufacturers only have to indicate on the label the ingredients that they include in their formulation. Those additives that are contained in purchased raw materials do not have to be indicated (8).
Since vitamin D is one of the fat-soluble vitamins, it should be ingested in a combination with oil (5). Therefore, high-dose vitamin D is available on the market in drops or capsules containing oil. The capsules are particularly suitable for very high doses, as they can be used to avoid overdosing. The advantage of drops is that they can be dosed individually and most products have a very pure and high quality. They are also very suitable for people who do not like to swallow capsules and for children. Care should be taken to use pure MCT oil as a carrier. Other vegetable oils oxidise and can destroy the active ingredients of the vitamin (1).
Guide: Frequently asked questions about high-dose vitamin D answered in detail
In order to inform you comprehensively about the effectiveness of high-dose vitamin D and to give you an understanding of the current state of science, we have summarised all the important information in the following sections.
What is high-dose vitamin D and how does it work?
When vitamin D is formed, provitamin D3, a precursor of vitamin D, is first produced in the skin. Via the bloodstream, provitamin D3 reaches the liver and kidneys. There it is converted into the biologically active vitamin D, the so-called calcitriol. A vitamin D deficiency can be detected by a blood test (3). The following table shows the functions of vitamin D in the body.
|Intestine||Vitamin D is involved in the absorption of phosphate and calcium from food in the intestine.|
|Bones and teeth||Vitamin D ensures the incorporation of calcium into bones and teeth.|
|Musculature||vitamin D helps supply calcium to the muscles.|
|Immune system||vitamin D is involved in the maturation and differentiation of defence cells.|
|Hormonal system||vitamin D regulates insulin, thyroid hormones, and parathyroid hormone in the body.|
These are a few examples that illustrate the importance of an adequate supply of vitamin D for various body processes.
When and for whom is it useful to take high-dose vitamin D?
- For children and adults: If the vitamin D status in the body is not considered deficient, about 20 micrograms (800 International Units, IU) of vitamin D3 is recommended. However, this estimate is based on the assumption that no endogenous vitamin D is produced in the body (3).
- For older people: At an older age of over 65 years, vitamin D can help prevent falls and fractures. Vitamin D supplementation of 10-20 micrograms (400-800 IU) per day is recommended (3).
- During pregnancy: To ensure the healthy development of the child in the womb, an adequate supply of vitamin D is essential (4). During pregnancy, a vitamin D intake of 20 micrograms (800 IU) is recommended (3).
- During breastfeeding: A sufficiently high supply of vitamin D is particularly important during breastfeeding because the vitamin D content of breast milk depends on the mother's vitamin D status. For infants in their first year of life, 10 micrograms (400 IU) of vitamin D supplements daily are recommended (3).
These were some examples of groups of people for whom vitamin D supplementation may be useful. In any case, the amount of vitamin D dosage should be discussed with a doctor beforehand.
What are the possible side effects of taking high doses of vitamin D?
A distinction is made between acute and chronic vitamin D overdose. A daily intake of more than 100 mg vitamin D, for example, increases the risk of kidney stones (7). A vitamin D overdose can lead to various negative health effects, which are mostly due to an increased calcium level in the blood. This is because the excess vitamin D allows the body to absorb more calcium from food and release it from the bones (7). The following side effects can be observed with vitamin D excess:
- Nausea and vomiting
- Loss of appetite
- strong thirst
- increased urine production
- Feeling of weakness
- Kidney stones and kidney damage
Of course, these side effects do not have to occur and depend on the level of the vitamin D overdose.
How much do high-dose vitamin D products cost?
|Vitamin D drops||7€ to 13€|
|Vitamin D capsules||13€ to 40€|
Vitamin D drops are generally somewhat cheaper than vitamin D capsules and are usually available in 50 ml units. Capsules are largely offered in 120 or 180 piece packs.
What types of high-dose vitamin D are available?
You can buy vitamin D either in the form of drops or capsules. Care should be taken to use pure MCT oil as a carrier, as other vegetable oils can oxidise and destroy the active ingredients of the vitamin (1).
|Vitamin D drops||Vitamin D drops can be dosed individually. They are very suitable for people who do not like to swallow capsules and for children.|
|Vitamin D capsules||For higher doses of vitamin D, it makes sense to opt for vitamin D capsules to avoid overdosing.|
Furthermore, high-dose vitamin D supplements can be classified according to their active ingredient. Here, the active ingredient vitamin D3 or vitamin D3 vegan is preferred to the active ingredient vitamin D2. The latter has a significantly higher bioavailability and effectiveness. (2) .
What alternatives are there to high-dose vitamin D?
In winter, the number of hours of sunshine and the intensity of sunlight is lower. In this case, vitamin D deficiency can occur, but it is detected by a blood test at the doctor's office. If a deficiency is detected, vitamin D supplements can help to cover the daily vitamin D requirement (5).
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Hemery YM, Fontan L, Moench-Pfanner R, Laillou A, Berger J, Renaud C, Avallone S. Influence of light exposure and oxidative status on the stability of vitamins A and D₃ during the storage of fortified soybean oil. Food Chem. 2015 Oct 1;184:90-8. doi: 10.1016/j.foodchem.2015.03.096. Epub 2015 Mar 28. PMID: 25872430.
Laura A. G. Armas, Bruce W. Hollis, Robert P. Heaney, Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans, The Journal of Clinical Endocrinology & Metabolism, Volume 89, Issue 11, 1 November 2004, Pages 5387–5391
EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2016. Scientific opinion on dietary reference values for vitamin D. EFSA Journal 2016; 14( 10):4547, 145 pp.
Wagner CL et al: Vitamin D and its role during pregnancy in attaining optimal health of mother and fetus. Nutrients 2012; 4(3): 208-30
Stückler D., s.a., Einfluss des Sonnenverhaltens auf den
Vitamin D Status
Chen TC et al: Factors that influence the cutaneous synthesis and dietary sources of vitamin D. Arch Biochem Biophys 2007; 460(2): 213-217
Wenchel R., 2019. Antworten des Robert Koch-Instituts auf häufig gestellte Fragen zu Vitamin D
Stiftung Warentest Rückstände aus Verpackungen – Da geht was rein. https://www.test.de/Rueckstaende-aus-Verpackungen-Da-geht-was-rein-1240626-2240626/.
Klöting N, Hesselbarth N, Gericke M, et al (2015) Di-(2-Ethylhexyl)-Phthalate (DEHP) Causes Impaired Adipocyte Function and Alters Serum Metabolites. PLOS ONE 10:e0143190
Dolan SP, Nortrup DA, Bolger PM, Capar SG. Analysis of dietary supplements for arsenic, cadmium, mercury, and lead using inductively coupled plasma mass spectrometry. J Agric Food Chem. 2003 Feb 26;51(5):1307-12. doi: 10.1021/jf026055x. PMID: 12590474.