Supplements: Dosage, Risks & What Doctors Recommend

The supplement aisle can feel like a pharmacy, brimming with bottles promising everything from better immunity to improved sleep. But unlike medications, vitamins and nutritional supplements – often referred to as dietary supplements – operate under a different set of rules, and that difference carries significant implications for consumer safety. While they might offer health benefits, they also pose potential risks, and understanding those risks is crucial.

Frei verkäuflich heißt nicht sicher

Despite appearing and being packaged like medications, dietary supplements are regulated as food products, not drugs. So their effectiveness and safety aren’t proactively reviewed by regulatory bodies before they hit the market. Instead, manufacturers simply notify the German Federal Institute for Risk Assessment (BVL) with basic information: name, address, product name, ingredients, quantities, and a label. There’s no verification of ingredient accuracy or dosage correctness.

The BVL states explicitly that “no testing or approval by an authority takes place before the first placing of dietary supplements on the market.” Oversight relies on sporadic sample testing by local food surveillance authorities. This lax regulation has been criticized for years by consumer advocates, scientists, and politicians, as it creates opportunities for abuse. Products containing dangerous contaminants repeatedly surface. The German Federation of Consumer Organisations documents numerous violations monthly, finding substances like carcinogenic materials, salmonella, lead, and even ingredients that shouldn’t be in supplements at all – such as sildenafil (the active ingredient in Viagra) or sibutramine, an appetite suppressant banned in 2010 due to life-threatening side effects.

Die Dosis macht das Risiko

Protecting yourself from overdoses requires awareness of two key figures: the German Nutrition Society’s (DGE) recommended daily intake and the maximum amounts established by the German Federal Institute for Risk Assessment (BfR). The latter represents the upper limit beyond which a supplement could become harmful. While manufacturers should adhere to these limits, they aren’t legally obligated to do so. This has led to significant discrepancies. A 2020 study by researchers at Schwäbisch Gmünd University of Education examined 106 different supplements and found that over half exceeded the recommended maximum levels for at least one nutrient, with some being 700 percent over the limit. Multivitamin preparations were particularly problematic.

There’s a glimmer of hope on the horizon. The EU is expected to introduce legally binding maximum levels for certain supplement ingredients this year, including selenium, vitamin B6, vitamin A/beta-carotene, vitamin E, vitamin D, and iron. It’s also important to note that the actual amount of ingredients in a supplement can deviate from the label by up to 50 percent – a difference not seen with medications.

Erst mal beim Arzt abklären

Determining whether you need a vitamin pill without a medical evaluation is difficult. Symptoms like fatigue, muscle cramps, or hair loss don’t always indicate a deficiency. Conversely, you might have a deficiency you’re unaware of. Individuals with obesity, for example, often have low vitamin D levels because it’s stored in fat tissue. Conditions affecting the pancreas, liver, or gallbladder can also hinder nutrient absorption. People with Crohn’s disease or celiac disease are also more prone to deficiencies.

A dietary record, physical examination, and laboratory tests can provide clarity. Depending on the nutrient, blood, urine, or tissue samples may be analyzed. However, test results aren’t always reliable and can be influenced by external factors. Zinc levels, for instance, are often lower during an infection, while ferritin levels (an indicator of iron deficiency) can increase with a cold.

It’s crucial to inform your doctor about any supplements you’re taking. Biotin, for example, can interfere with lab tests, including those for heart attacks and thyroid function. Some supplements can also interact with medications. High-dose antioxidants may reduce the effectiveness of cancer therapies.

Wenn Nahrungsergänzungsmittel krank machen

In 2022, a critically ill infant was admitted to an intensive care unit, as reported by the German Doctors’ Journal. The baby had lost weight, experienced altered consciousness, was dehydrated, had kidney calcification, and exhibited abnormal potassium and calcium levels. The parents had been administering vitamin D drops in a dose 80 times higher than recommended, based on advice from friends. This case represents the tip of the iceberg.

“I frequently see abnormal blood values – almost always because patients are taking dietary supplements,” says Diana Rubin, a nutritional medicine specialist at Vivantes Hospital in Berlin. Patients with chronic, difficult-to-treat illnesses are particularly susceptible to marketing claims. “Approximately half of the patients in our clinic have taken an excessive dose of a dietary supplement,” notes Bernhard Schieffer, who runs a post-COVID outpatient clinic at Gießen-Marburg University Hospital. He has observed a trend of liver and vascular damage caused by seemingly harmless products like curcumin, folic acid, or resveratrol. He also frequently finds elevated blood lipid levels due to excessive intake of fish oil capsules with omega-3 fatty acids.

Oncologist Jutta Hübner, an expert in complementary cancer therapies at Jena University Hospital, warns not only of side effects but also of interactions with cancer treatment. High doses of antioxidants like vitamin C can diminish the effectiveness of chemotherapy and radiation therapy, potentially worsening a cancer prognosis. She advises discussing any alternative therapies with the treating physicians.

Wann Ergänzungen wichtig sind

Infants require essential minerals, and vitamins. Four “critical nutrients” often necessitate supplementation, according to the German Federal Health Bulletin: iodine for breastfeeding mothers or in complementary foods, vitamin D (around 12 micrograms daily) until the second summer, vitamin K in the first few weeks of life, and fluoride as long as toothpaste isn’t used. Pregnant women should ideally start taking folic acid four weeks before conception, along with iodine and iron if deficient.

As people age, their energy needs decrease while their nutrient requirements remain the same. Depending on lifestyle, they may lack vitamin B12, iron, calcium, and protein. Vitamin D is crucial for preventing bone loss, especially in nursing homes where seniors rarely get fresh air. Vegans need vitamin B12 and iodine in pill or powder form, and often don’t get enough calcium and vitamin D through diet alone.