There has just been a large study published stating that the taking of calcium supplements gives a 30% increased risk of a heart attack and an increased risk of strokes also. I can look it up if anyone is interested.

I have been taking 1000mg of calcium supplements a day for years......I thought I was doing the right thing for my bones. You can't win!

She sounds like she was wise before her time.

D2 or D3?
Several years ago, studies indicated that, at very high doses (4,000 IU per day for two weeks or a single dose of 50,000 IU), the D3 form of vitamin D is more efficient at maintaining serum 25-hydroxyvitamin D levels, than the D2 form.2,3 However, a more recent and longer term study using a more common dosage, 1,000 IU daily, showed the two forms to be equally effective at raising and maintaining serum levels.5 An even more recent study showed that the two forms are also equally efficient whether taken daily as an oral supplement or in a fortified orange juice, based upon a dose of 1,000 IU per day.7

Deficiency vs. Insufficiency: Serum levels of 25-hydroxyvitamin D
After being ingested, both vitamin D2 and D3 are metabolized in the liver to form 25-hydroxy vitamin D and in the kidneys to 1,25-hydroxy vitamin D. Serum levels of 25-hydroxyvitamin D (also referred to as 25-(OH)D) are commonly used clinically to evaluate vitamin D status. A level below 15 ng/ml is considered deficient as it is too low to for bone health or overall health. Even levels below 30 ng/ml are considered insufficient (though not “deficient"). Levels of 30 ng/ml or above are considered desirable. [Another way of expressing these levels is in nanograms per liter: 1 ng/mL = 2.5 nmol/L, so 30 ng/mL = 75 nmol/L.] Levels above 200 ng/mL (500 nmol/L) are considered too high.8

Although a small percentage of the population is believed to be deficient in vitamin D, a large percentage of the population is believed to have vitamin D insufficiency. It was recently reported that 61% of America children and adolescents had insufficient levels of vitamin D (based 25-(OH)D levels) and an additional 9% were deficient. Deficient children tended to have higher blood pressure and lower levels of HDL ("good") cholesterol than other children. Older children were more likely to be deficient, as were those who were obese, drank milk less than once a week, or spent more than four hours a day with TV, video, or computers. Those who used vitamin D supplementation were less likely to be deficient.4

A rule of thumb for raising serum levels of 25-hydroxyvitamin D is that about 100 IU of vitamin D2 or D3 daily will raise serum levels by 1 ng/ml in an adult. With moderate (1,000 IU per day) supplementation, it has been shown to take about 6 weeks for serum levels to reach their peak. For example, during winter with no significant sun exposure, supplementation with 1,000 IU has been shown to increase levels of around 20 ng/mL up to about 30 ng/ml at six weeks. In such a scenario, sun exposure or a dosage higher than 1,000 IU would be necessary to further elevate levels above 30 ng/mL.5