Sundown Vitamin D3 25 mcg 1000 IU Review

Vitamin D is the only ingredient, and this product gives it at a dose that has worked in studies. In people with type 2 diabetes, two large pooled analyses of 46 trials of 4,313 people and 39 trials of 2,982 people found that vitamin D modestly lowered fasting blood sugar, the long-term blood sugar marker and insulin resistance ^[1][2]. The benefit was largest in people low in vitamin D, in overweight people, and with high doses over a short time, so a daily 1000 unit dose may do less ^[1][2]. In adults with prediabetes, three placebo-controlled trials found about 15% less risk of developing diabetes over about 3 years ^[3]. In pregnant women, 53 trials of 9,443 women found about 36% less pregnancy diabetes ^[4]. Not all results agree. A trial of 22,220 older adults taking 2000 units daily for about 5 years found no significant drop in diabetes risk, though pooling it with earlier trials showed a modest reduction ^[5]. A pooled analysis of 1,580 people with prediabetes found no change in fasting blood sugar or the long-term marker, though the glucose tolerance test improved ^[6]. Animal and cell studies are never counted.

Vitamin D3 is the only ingredient here, and the panel leans toward it: most of the ten recommend it or take it themselves, and the rest are neutral. People take it because food and sunlight often fall short, especially in fall and winter or for those who avoid the sun, and they link it to bones, muscle, immune function, brain health and mood. Doses vary widely, with three of them taking 5000 IU in the morning, one advising at least 10,000 IU a day, and several aiming for blood levels well above what is called normal. Because it is fat soluble, one panelist says to take it with dietary fat rather than alone with other supplements, and two pair it with vitamin K2. One panelist cautions that for most purposes there is no point supplementing unless you are actually low, and no one said they stopped taking it.