Douglas Laboratories D-Replete Vitamin D 5000 IU

Our assessment

The evidence shows that this product is a high-dose vitamin D supplement. While vitamin D is crucial for health, the 5000 IU dose exceeds the typical recommended daily allowance, so we advise you to use it only under professional guidance. Data for the specific ingredient calcium is included in the product label, but the primary active ingredient for this supplement is vitamin D at a high potency.

How it works

Vitamin D acts as a master regulator in your body. It supports bone health by helping you absorb calcium, which is critical for bone mineralization and neuromuscular relaxation [NIH ODS]. Think of it as a key that unlocks your body's ability to use calcium effectively for strong bones and healthy muscle function [NIH ODS].

Safety profile

Data not available for specific adverse event reports for this exact product. However, the FDA has received a total of 592,059 adverse event reports across all dietary supplements, which underscores the importance of being cautious [FDA data]. For the ingredient calcium, high levels can cause constipation, nausea, weight loss, and abnormal heart rhythms [NIH ODS]. Because this is a 5000 IU dose, you should be aware that very high vitamin D intake over time can lead to calcium buildup in the blood, with risks including poor kidney function and extreme tiredness [NIH ODS].

Our recommendation

Start by having your blood levels of vitamin D checked. A dose of 5000 IU is typically recommended for correcting a deficiency, not for general maintenance. Do not combine this supplement with other high-dose vitamin D products without medical supervision. If you take medications like bisphosphonates or thyroid medication, be aware that calcium can affect their absorption, so take them at separate times [NIH ODS]. Our clear advice: use this only if a healthcare provider has confirmed you need this high dose.

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