Nature Made Vitamin D3 2000 IU (50 mcg), 250 Vitamin D Softgels

Nature Made Vitamin D3 2000 IU is one of the most-reviewed vitamin D supplements on Amazon. A 250-softgel bottle costs about $16, which works out to roughly 6 cents a day, and it holds a 4.8-star average from around 40,000 reviews.

What you get

Each softgel contains 2,000 IU (50 mcg) of vitamin D3, the form your skin makes from sunlight. The listing says it's gluten free, with no color added and no artificial flavors. The bottle carries the USP Verified mark, meaning the United States Pharmacopeia has independently checked that the product contains what the label says and meets its standards for purity and manufacturing.

Nature Made's directions are one softgel a day with water and a meal, ideally one with some fat in it, since vitamin D is fat-soluble.

How the dose compares to the limits

The NIH Office of Dietary Supplements recommends 600 IU (15 mcg) a day for adults up to 70 and 800 IU over 70. The upper limit for adults is 4,000 IU (100 mcg) a day from all sources. At 2,000 IU, this softgel sits above the recommended intake and at half the upper limit. If you also take a multivitamin or a calcium-plus-D product, add those amounts in.

Like all supplements, it isn't approved by the FDA before sale, and the listing's health claims haven't been evaluated by the FDA.

Who it's for

• Adults who get little sun, especially through winter in northern states
• People with darker skin or who are older, who tend to make less vitamin D from sunlight
• Anyone whose doctor has suggested a daily vitamin D maintenance dose

Who should skip it

If you already take a high-dose vitamin D product, or your doctor has you on a prescription dose, don't stack this on top. People with kidney disease, sarcoidosis or high calcium levels should ask their doctor before taking vitamin D at all. And if you're tired all the time, get a blood test before assuming vitamin D is the answer. Our guide to why you're always tired covers the other usual causes.

Alternatives

If you'd prefer a lower dose, the Thorne Vitamin D-1,000 gives you 1,000 IU per capsule from a brand that third-party certifies its products, for about $17 for 90. For a multivitamin that includes vitamin D alongside other nutrients, see the Nature Made Multivitamin For Her.

For how vitamin D compares with iron and B12 as a cause of fatigue, read iron, B12, or vitamin D: which supplement for energy. Our full picks are in the best vitamins for energy and tiredness.