Vitamin D products – when are they useful?

There is much and sometimes controversial discussion about vitamin D. In particular, some suppliers of dietary supplements are driving the debate about a supposedly necessary additional intake of vitamin D supplements. Therefore, we always deal with the latest studies and nutritional recommendations of professional societies independently and free of sales interests and adapt our articles and recommendations if this is necessary in the interest of consumer-oriented and supplier-independent information. All sources can be found at the ending of the article.

What is behind the advertising of vitamin D products?

Advertising constantly suggests that the majority of the population will gain health benefits from taking vitamin D supplements.

The following health claims are allowed on vitamin D supplements (and on fortified foods), provided they contain at least 0.75 µg per daily dose (NEM) or 0.75 µg per 100 g liquid foods 0.375 µg per 100 ml): Vitamin D:

1.contributes to normal absorption/utilization of calcium and phosphorus

2.contributes to normal blood calcium levels

3.contributes to the maintenance of normal bones

4.contributes to the maintenance of normal muscle function

5.contributes to the maintenance of normal teeth

6.contributes to a normal function of the immune system

7.has a function in cell division

8.contributes to normal immune system function in children

helps reduce the risk of falls due to postural instability and muscle weakness. falls are a risk factor for fractures in men and women 60 years and older (at 20 µg/day)

A recent Danish study has also just shown that supplemental vitamin D has no positive effect on muscle health or strength.

Vitamin D is needed:

• Normal growth in children, without which bones and teeth do not mineralise properly,
• Healthy teeth, because it contributes to the synthesis of enzymes in the mucous membrane that actively transport available calcium,
• Normal heart function and blood clotting,
• maintaining a stable nervous system and blood pressure,
• contributes to the normal functioning of the immune system,
• participates in the process of cell division,
• contributes to muscle function.

A winter energy set that is supposed to help against mood swings

“However, the BfR is currently not aware of any studies that prove that taking vitamin D supplements protects against infection with this virus or against triggering the disease. It is scientifically undisputed that vitamin D contributes to the normal function of the immune system and that an adequate vitamin D supply is important for health. However, this does not mean that people should therefore take high-dose vitamin D supplements as a preventive measure and without medical supervision. Case reports indicate that taking vitamin D supplements independently at very high doses may pose health risks.”

“Indeed, the current state of studies suggests a potential association between low serum vitamin D levels and an increased risk of SARS-CoV-2 infection or severe COVID-19 progression. However, the results are not sufficient to demonstrate a clear cause-and-effect relationship. This is also supported by the statements of other expert institutions such as the Federal Institute for Risk Assessment (BfR) or the Robert Koch Institute (RKI).” […] “In individuals with adequate vitamin D status of ≥ 50 nmol 25(OH)D/l in serum, it has not yet been proven that taking a vitamin D 20 000 supplement has an additional benefit in this regard.”

vitamin D supplements

Prof. Dr. Jakob Linseisen, president of the DGE, says: “Supplementation of vitamin D at the reference level of about 20 µg (800 IU) daily may […] be necessary to ensure an adequate vitamin D status. So, assuming a causal relationship, adequate vitamin D status would have a preventive effect on the risk of SARS-CoV-2 infection or severe COVID-19 progression.”

The treatment successes in covid-19 intensive care patients noted in a yet-to-be-publish. Scientifically controversial Spanish study were achieve with a specific vitamin D compound (calcifediol). That is not allow in dietary supplements. Also, an American RCT study does not support. The use of high doses of vitamin D3 to treat COVID-19 in hospitalized patients. So, Cochrane systematic review from May 2021 provides a good overview.

Vitamin D is necessary for the absorption of calcium and phosphorus. In other words, vitamin D promotes the absorption of excess calcium in the body into the bones. If the body is deficient in vitamin D, the deposition of calcium in the blood vessels is favor. Which can accelerate the development of atherosclerosis. Vitamin D is particularly important in childhood and adolescence. When bones develop rapidly, which is the basis for healthy and strong bones in old age. So, vitamin D is deficient, proper calcium intake is of little benefit.