Three important nutritional supplements: Omega-3, Vitamin D and Vitamin C

Long chain omega-3 fatty acids: EPA and DHA

EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are long-chain, polyunsaturated omega-3 fatty acids. They are components of cell membranes and are involved in various signaling and regulatory processes. DHA is found in particularly high concentrations in the brain and retina. While the plant-based omega-3 fatty acid ALA is found, for example, in linseeds, chia seeds and walnuts, fatty fish and certain microalgae in particular provide EPA and DHA directly.

Algae oil is a plant-based source of EPA and/or DHA that is suitable for vegans. The quality of an oil depends, among other things, on the raw material, production, storage and oxidation stability. Products with transparent information on EPA and DHA quantities as well as traceable quality and purity tests make sense. A specific manufacturer cannot be generally classified as particularly recommendable without independent, current test data.

People who don't eat fish can use algae oil as a direct source of EPA and DHA. Whether a supplement is necessary depends on the individual diet and supply. For healthy adults, there is no consistent recommendation that every person must take an EPA/DHA supplement. Regardless of this, the essential plant-based omega-3 fatty acid ALA should be consumed sufficiently through food.

Omega-3 fatty acids can lower triglyceride levels. However, the study situation on the prevention of heart attacks, strokes or other cardiovascular events through over-the-counter supplements is differentiated: large studies and meta-analyses do not consistently show a relevant benefit for all healthy people. Certain high-dose prescription EPA preparations may have benefit in select individuals at high cardiovascular risk; These results cannot easily be applied to every dietary supplement.

During pregnancy, DHA and other long-chain omega-3 fatty acids are relevant for the child's development. Studies show that adequate intake can reduce the risk of premature birth. However, the evidence for improving children's IQ through fish oil supplements is not clear. Pregnant women who do not eat fish should discuss their DHA or EPA supply with their healthcare professional.

Further information: NIH: Omega-3 fatty acids - technical information.

Vitamin D: Particularly relevant with low sun exposure

Vitamin D is important for calcium and phosphate metabolism and therefore for maintaining normal bones. It also contributes to normal muscle function. Unlike most vitamins, the body can produce vitamin D itself in the skin using UV-B radiation. In Germany, this formation is often severely restricted in winter due to the low position of the sun.

However, this does not mean that every person automatically develops a vitamin D deficiency in winter or should take high doses of supplements. Care depends, among other things, on time spent outdoors, skin type, age, clothing, diet and other individual factors. For example, people who rarely spend time outdoors or rarely expose their skin to the sun have an increased risk of inadequate care.

The German Society for Nutrition gives an estimated value of 20 micrograms (800 IU) of vitamin D per day if the body's own production is lacking. This value is not a general intake requirement for all people, but rather applies under the assumption that the skin does not produce vitamin D. Supplementation is particularly considered when an adequate supply cannot be achieved through the body's own education and nutrition.

The intake of 60,000 IU per week for one month mentioned in the original text is not a general self-medication recommendation and should not be adopted across the board. High-dose treatments may be prescribed by a doctor in certain medical situations. Such high doses are unsuitable for independent, long-term use: an overdose can lead to increased calcium levels in the blood and other health problems. The Federal Institute for Risk Assessment advises against high-dose bolus doses without medical indication and points out possible risks.

Further information: DGE: FAQ Vitamin D and BfR: Vitamin D – sun and exercise promote good supply.

Vitamin C: Important, but usually readily available through food

Vitamin C (ascorbic acid) is an essential nutrient. Among other things, it is needed for collagen formation, wound healing, normal immune system function and the absorption of non-heme iron from plant foods. It also acts as an antioxidant. Good sources include peppers, broccoli, brassicas, berries and citrus fruits.

If you regularly eat enough fruit and vegetables, you can usually cover your vitamin C needs through your diet. Supplementation can make sense if the intake is permanently too low or there is an increased need or a medically justified risk. For example, people who smoke have a higher need for vitamin C than non-smokers.

Higher doses are not automatically healthier. There is insufficient evidence to support the claim that high oral doses of vitamin C reliably prevent or treat cancer, cardiovascular disease or Alzheimer's disease. For colds, regular use can, on average, slightly shorten the duration of symptoms; However, in the general population it does not reliably prevent colds. Studies have shown that taking it after the cold has started has shown no consistent benefit.

Very high amounts can cause gastrointestinal problems. In people with certain medical conditions, such as iron overload (hemochromatosis), high doses of vitamin C may pose additional risks. Therefore, taking high doses without a specific reason is not recommended.

Unlike many other mammals, humans cannot produce vitamin C themselves and must obtain it through food. However, the comparison with the body's own vitamin C production in animals cannot be directly converted into a human supplement requirement.

Further information: NIH: Vitamin C - Summary of Product Characteristics and Cochrane: Vitamin C for colds.

Conclusion: need instead of blanket supplementation

Omega-3 fatty acids, vitamin D and vitamin C fulfill important tasks in the body. Nevertheless, they are not equally necessary as a dietary supplement for all people. If you are on a vegan diet, algae oil can be a way to directly absorb EPA and DHA. Vitamin D is particularly an issue when the body's own production is not sufficient. If you eat a varied diet, you can usually easily get vitamin C from fruits and vegetables.

The most sensible strategy is therefore not to take as many medications as possible, but rather to specifically identify possible gaps in care and close them as needed. If you are pregnant, ill, taking medication or are unsure about the dosage, supplementation should be accompanied by medical or nutritional advice.