When is the best time to take a calcium supplement with vitamin d supplement?

It depends. Most vitamin d3 supplements are best taken with food. Calcium carbonate should be taken with food, so you may take both at the same meal. Calcium citrate can be taken with or without food.
For a lot of reasons. Calcium plays a vital role in body function. It regulates muscle contraction, nerve conduction and bone health among others. Both calcium and vitamin d should be taken with a meal (only exception will be calcium citrate which can be taken on empty stomach).

Related Questions

What is the best calcium supplement with vitamin d for a 63-year-old woman?

D3. It seems that the latest information has been that D3 is what is best for the body - also called cholecalciferol. So you want a calcium with d3. Also, magnesium is an important mineral for bone health as well. As far as which supplement is the best, it is very difficult to say. An excellent resource is nutrisearch's comparative guide to nutritional supplements.
Lots to choose from. As long as you are getting between 1000-1200mg of calcium daily in divided doses and 2000-5000 units of vitamin d daily you should be in good range. A blood sample before and 3 months after supplementation would be recommended. Also make sure you are doing 30 mins of weight bearing exercise at least 3 times a week for optimal bone health.

Can I take one tablet calcium supplement with vitamin D any risk for heart attack and stroke?

Yes. Calcium 600mg with vitamin D3 400 international units can be safely taken once daily. For people in areas of the US where there is little light- especially during winter, you might consider twice a day. This calcium and vitamin D should not lead to risk of heart attack, smoking and being on the birth control pill might.

Will your body absorb a calcium supplement if you take vitamin d with it?

Yes. The short answer is yes. Although not directly as the vitamin d in your supplement (which is either D3 or d3) has to be converted first by your body (in the kidneys) to the active form of vitamin d (called calcitriol). This latter product will in turn aid in the absorption of calcium in the gut.
See below. The body absorbs calcium better with adequate vitamin d administration.
Food BestSource Ca+2. Yes, D3 needed for absorption & often ↓ in US, but best measure vit. D3 concentration; optimal in the 70-80 ng/ml range. Sun tends to trigger conversion of a little cholesterol in skin to Vit D, then converted in liver to D2 & by kidneys & other tissues to D3. D3 impt for Ca absorption, bone & muscle strength + immune function. Best source food & if D3 conc good, unlikely need Ca+2 supplements.

Is it really important to take vitamin d with calcium supplement? Is it serious if you do not?

The D3 is important, not the calcium supplement. D3 required for intestinal cells to absorb calcium from food, the bone forming cells to form bone, muscle (including heart) strength, immune function. However too much can be toxic. Thus do not blindly take. Instead check & optimize blood concentrations (by blood sample) in upper normal, e.g. 70-80 ng/ml, range. If D3 good, calcium pills likely a waste of money.

I heard that you are supposed to take vitamin d with calcium supplement. What if you do not is it serious?

Calcium & Vit D. No, it is not serious. You should be getting calcium from the foods you eat anyway. Vit D has an effect on calcium so it may be beneficial to add a supplement but if you get good you should be good.

I have heard to take vitamin d and calcium supplement together. Is it really bad if I do not? Because I only take vitamin d with vitamin c.

Vitamin therapy. Vit D is a fat soluble vitamin so it is best absorbed with a high fat meal and levels seem to do better if taken with supper. Vit C is water soluble and therefore excreted if you take too much at one time. Taking both together would probably decrease absorption of both so should be taken at separate times. Calcium would be better absorbed taken with Vit C since it is an acid.

Is it really important to take vitamin d and calcium supplement together? What if you do not is it serious? But I take vitamin c and vitamin d together is this okay?

Vitamins combined in. All foods, beware lots of untrue promotions. If vitamin D3 (crucial to enable both calcium absorption from food & the bone forming cells to form bone; + other issues) concentrations are upper normal, e.g.70-80 ng/ml, then rarely even need Ca beyond within food. ↑ vitamin C rarely of any value for people living in 1st world countries; Lookup: "Linus Pauling & Vit. C"; actual evidence using Google.