Dr. Clark Research Association Dr. Clark Zentrum Vitamin B12 1 mg

Our assessment

The evidence shows that this product contains Vitamin B12 at 1 mg per serving, but the critical data provided relates to Calcium, not Vitamin B12. Based on the available information, we cannot make a direct assessment of Vitamin B12 benefits for this specific product. For the ingredient Calcium, our assessment is that it plays a key role in bone health, but you need to be careful with dosing to avoid potential risks [NIH ODS].

How it works

Think of Calcium as a structural builder and a nerve signaler. It supports bone mineralization and density, and it helps your muscles relax and your nerves send signals properly [NIH ODS]. This is important for maintaining strong bones and a healthy nervous system.

Safety profile

FDA received 592,059 total adverse event reports across all supplements. For Calcium specifically, high intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. High levels of calcium in your blood and urine can cause poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. Calcium can also reduce the absorption of medications like bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].

Our recommendation

Because the data provided is for Calcium and not the labeled Vitamin B12, our recommendation is limited. If you are taking this product for Vitamin B12, data not available. For Calcium, you should be aware of the potential side effects and medication interactions listed. Do not exceed recommended daily intakes without a healthcare provider's guidance, and consult your doctor if you take any of the medications that interact with calcium [NIH ODS].

Supplement labels contain several key sections regulated by the FDA:

• Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
• Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
• % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
• Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
• Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.

Source: FDA Dietary Supplement Labeling Guide