NOW Zinc 50 mg

Our assessment

The evidence shows that this product provides a high dose of calcium. For most adults, the recommended daily allowance for calcium is 1,000 mg, increasing to 1,200 mg for women over 50 and men over 70 [NIH ODS]. A 50 mg dose is well below these targets and is more typically seen in a trace mineral or supporting role. Our assessment is that this supplement is unlikely to provide meaningful bone health benefits on its own due to the low dose.

How it works

Think of calcium as a structural building block for your bones and a signal messenger for your nerves and muscles. It supports bone mineralization and density, and it helps your muscles relax and nerves communicate properly [NIH ODS]. However, to achieve these effects, you typically need several hundred milligrams per day from food and supplements combined.

Safety profile

FDA has received 592,059 total adverse event reports for products containing calcium. The safety data shows that high calcium intakes might increase the risk of heart disease and prostate cancer. High levels of calcium in the 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 several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].

Our recommendation

We recommend you do not rely on this 50 mg supplement alone for your calcium needs. For bone health, aim to get 1,000 to 1,200 mg of calcium daily from food sources like dairy, leafy greens, or fortified products. If you do use this supplement, take it separately from any medications listed in the interactions section. For a more effective approach, consider a standard calcium supplement with vitamin D, and always check with your doctor before starting any new regimen [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