Vitamin D3

What this is. Plain vitamin D3 at 4,000 IU. The nutrient most commonly low in anyone who does not get much sun, and taken for bone and immune health.

4,000 IU of vitamin D3 in a single capsule. The label prints it as 100 mcg, because that is the unit the FDA now requires — they are the same amount. Both are here so you can compare this with whatever else you are looking at.

What you are actually getting, per capsule

• Vitamin D3 (as cholecalciferol) — 100 mcg, which is 4,000 IU (500% of the Daily Value)

Worth knowing before you buy

4,000 IU is a high daily dose, not a starter dose. It sits right at the tolerable upper intake level set for adults — 4,000 IU a day from all sources combined. That last part is the bit people miss.

So before you add this: check your multivitamin, and check any calcium supplement you take. Both routinely contain vitamin D, and the totals add up faster than you would expect.

If you want the lower dose, our Vitamin D with Magnesium is 2,000 IU — half this — and it is the more sensible starting point for most people who are not working from a blood test.

D3 (cholecalciferol) is the form your skin makes from sunlight, and it raises blood levels more reliably than D2. That part of the label is doing real work.

How to take it

One capsule daily with 6–8 oz of water, ideally with a meal that contains some fat. 30 capsules — a 30-day supply.

Other ingredients

Gelatin (capsule), brown rice flour. The capsule is gelatin, so this one is not suitable for vegetarians.

Cautions

Vitamin D is fat-soluble, which means it builds up in the body rather than washing out. Do not stack this with another vitamin D supplement without asking someone qualified first. It also interacts with certain medications, including some blood thinners. If you do not know what your vitamin D level is, a blood test is cheap and takes the guesswork out.

Keep out of the reach of children. Do not use if the safety seal is damaged or missing. Store in a cool, dry place. Do not exceed the recommended dose. If you are pregnant, nursing, under 18 or living with a medical condition, speak to your doctor or pharmacist first.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.