Who should not take vitamin D?

Ask a clinician before taking vitamin D if you have high blood calcium, kidney disease, a history of kidney stones, sarcoidosis or another granulomatous condition, or if you take a thiazide diuretic or any other vitamin D product. Most healthy adults are not in these groups; in these cases the usual numbers may not apply.

People who should check first

High blood calcium, or a condition that raises it

Vitamin D raises calcium absorption, so it is the wrong thing to add on your own if your calcium is already high. A 2018 clinical review describes vitamin D toxicity as the result of excessive intake, but also of conditions that produce the active vitamin D hormone locally, including granulomatous disorders such as sarcoidosis, and some lymphomas. In those conditions, ordinary doses can matter. The same review describes "hypersensitivity to vitamin D", where doses considered safe for the general population produce high calcium in people whose vitamin D metabolism is disordered. If you have any of these, a clinician decides whether and how much.

When calcium balance is already a concern

The kidneys convert vitamin D into its active form (NIH Office of Dietary Supplements), so kidney disease changes how vitamin D and calcium are handled, and who should supplement is a clinician's decision. On stones, the evidence is mixed. In the Women's Health Initiative (36,282 postmenopausal women, 400 IU of vitamin D3 with 1,000 mg of calcium for seven years), kidney stones were more common (hazard ratio 1.17, 95% CI 1.02 to 1.34), though that trial used calcium too. In a 2023 meta-analysis of 22 trials at 3,200 to 4,000 IU of D3 a day, stones and high urinary calcium did not differ significantly from control. If you have had stones, ask before adding it.

People taking certain medications

Thiazide diuretics reduce calcium loss in urine, and so can add to the effect of vitamin D on calcium. In one analysis, 84 people taking hydrochlorothiazide with up to 4,000 IU of D3 a day for three months had slightly higher calcium than people not taking it, with one case of hypercalcemia. Other medicines matter too: see vitamin D and medications: what to check.

Anyone already getting vitamin D elsewhere

The adult upper limit is 100 mcg (4,000 IU) a day from all sources. Count vitamin D from multivitamins and any other product. Our Personal Routines "D Complex" pill carries 125 mcg (5,000 IU) alone, over the limit, so do not take it with our Vitamin D3 softgel: together they come to 175 mcg a day.

Pregnant, nursing or under 18

The warning on our label tells people who are pregnant or nursing, or under 18, to ask a physician before use. We give no dosing or use guidance for those groups.

People who avoid animal products or particular oils

Our softgel is a gelatin capsule, so it is not vegan or vegetarian, and it is made with soybean oil and corn oil. The label does not state which animal the gelatin comes from, and it does not say what the vitamin D3 itself is sourced from (cholecalciferol is commonly derived from lanolin, which comes from sheep's wool). We have not confirmed either source, so we cannot answer a halal, kosher or sheep-free question from the label.

Who should take vitamin D3?

Nobody has to. The NIH ODS reference intake is the number to measure against, and a blood test of 25-hydroxyvitamin D is how a low level is found. The trials give no general reason to supplement a healthy adult: the largest, at 2,000 IU a day in about 25,000 US adults aged 50 and over who were not selected for low vitamin D, found no difference from placebo for cancer or cardiovascular events, and the follow-up analyses found none for fractures. Where vitamin D has shown a benefit, it was mostly in people who started very low. See vitamin D benefits: what the research does and doesn't show.

Our softgel at a glance

Electric Tiger Vitamin D3 has 50 mcg (2,000 IU) of vitamin D3 as cholecalciferol, 250% of the Daily Value and half of the adult upper limit, per softgel, as low as $15.35 a bottle on subscription. One softgel is the whole daily serving.

Questions people ask

Who should not take vitamin D3?

Anyone whose clinician has told them to avoid it, and the groups above should ask first. The label warning also directs people who are pregnant or nursing, or under 18, to ask a physician.

Is vitamin D3 bad for the kidneys?

Too much vitamin D raises blood calcium, and kidney disease changes how calcium and vitamin D are handled, so people with kidney disease or kidney stones should ask a clinician first. We cannot say that normal doses harm healthy kidneys. The trial evidence is mixed on stones, as above.

What not to take with vitamin D3?

Other sources of vitamin D, counted against the 100 mcg limit, and (as a matter to check with a clinician) high-dose calcium and thiazide diuretics, which add to calcium effects. The wider list is in the medications guide.

Which vitamin D3 does not come from sheep?

Ours does not state its source on the label, so we cannot say. Look for a product that names its source, and for vitamin D2 or a lichen-derived D3 if you avoid animal products.

What are the contraindications of vitamin D3?

The clearest are conditions with high blood calcium or conditions that produce active vitamin D on their own (such as sarcoidosis). Your clinician has the full picture of your history. We are not able to give a complete clinical list.