Not Always Healthy: 7 Supplements That Could Do More Harm Than Good

In the quest for better health, it’s easy to assume that dietary supplements are always beneficial. However, according to global wellness expert Dr. Eric Berg, some of the most commonly used supplements may

offer little benefit, and in fact might carry hidden risks. Here are 7 such supplements he recommends approaching with caution.

1. Synthetic Vitamin A (Retinol Palmitate / Acetate)

Although vitamin A is essential for vision and immunity, the synthetic forms may not be absorbed effectively. Accumulation of excess vitamin A in the liver or fat tissue is possible, and the natural-food route (for example eggs or cod liver oil) is considered safer.

2. Synthetic Vitamin B12 (Cyanocobalamin)

The standard supplement form ‘cyanocobalamin’ contains trace cyanide and may reduce the body’s protective glutathione levels. In contrast, the more bioavailable methylcobalamin form found in animal-derived foods is preferred.

3. Synthetic Iron (Ferrous Sulfate)

Though iron is critical, the synthetic ‘ferrous sulfate’ form may be harsh on the body, causing liver stress and potentially raising the risk of diabetes when taken excessively. Natural iron from red meat and liver can be easier on the system.

4. Folic Acid (Artificial Vitamin B9)

While folic acid is common in fortification and supplements, about one-third of people may carry a genetic variant in the MTHFR gene that impairs conversion to active folate. The inactive form may build up and raise cardiovascular risks; obtaining folate from leafy greens is advisable.

5. Magnesium Oxide & High-Dose Vitamin D2

Magnesium oxide is poorly absorbed and can lead to gastrointestinal issues. For vitamin D, the synthetic D2 form is less effective than D3, and excess may cause imbalances.

6. Synthetic Beta-Carotene

Beta-carotene naturally occurs in vegetables like carrots and provides the body with provitamin A. But its artificially produced counterpart has been linked in some studies to increased lung-cancer risk in smokers.

7. Calcium Carbonate

Used in many over-the-counter calcium supplements, calcium carbonate is derived from rock and may contribute to arterial or kidney mineral buildup over time, increasing risks of heart attack or kidney stones. Ultimately, supplements can help fill nutritional gaps, but they are not substitutes for a balanced diet rich in whole foods. Dr. Berg emphasises choosing nutrient-dense vegetables, lean proteins, nuts and seeds over relying on synthetic pills.