Currently I am taking a multivitamin, fish oil, and I recently added vitamin D supplements (D3 to be specific).

My current routine is take each of the three (along with some unrelated medication in pill form) after I eat breakfast each day.

The addition of the Vitamin D supplement has led me to wonder if taking all of these at the same time of the day is the best idea, or if it would be better to take them separately. For example, my multivitamin already has 400 IU of Vitamin D in it, and then I am adding another 1000 IU in the D3 pill.

Is my body capable of ingesting this much of the vitamin (along with everything else in the multivitamin) at the same time, or will some of it be wasted and end up being excreted? Would it be better to take one at morning and one at night?

  • Some medications can cause resistance to certain vitamins from being absorbed. You did not state your medication; if you do, I'm sure a better answer could be supplied. Due to the sources provided by md5sum, I recommend his answer. Mar 10, 2011 at 18:31
  • Vitamin D absorbs well with Calcium. Most people that are looking to gain muscle mass will take calcium in the morning so that they can take zinc and magnesium at night (the theory is the zinc will boost testosterone).
    – Adam Gent
    Mar 11, 2011 at 4:42
  • Which multivitamin? It is best to expose yourself to sunlight otherwise take butter, Ghee, chicken etc. Avoid Fish products since they are good source of toxin Methyl Mercury. Non soluable ones like Vitamin-D are like poison above a threshold.
    – AgA
    Dec 16, 2011 at 17:50
  • Ok I take hair skin and nails . Folic acid 500 and a kids multivitamin all at once in the morning could this be bad ?
    – user3900
    Jul 22, 2012 at 19:53
  • Off topic per new site rules in the FAQ.
    – Baarn
    Sep 20, 2012 at 18:41

2 Answers 2


You can take all of the listed various vitamins and supplements together. If you're only going to take them once a day, it is more beneficial to take them with your largest meal of the day, and that hopefully being dinner rather than with breakfast. (Source) (Source)

However, it is better to take smaller amounts with each meal than to take a single large dose once a day if at all possible. This way your body will maintain a more constant and stable supply of it's needed vitamins and nutrients.

You need to remember that some vitamins are fat-soluble (dissolve in fat) and some vitamins are water-soluble (dissolve in water). If you have a low-fat meal with your multivitamins, you're going to miss out on all the fat-soluble vitamins and only absorb the water-soluble ones. The reason you're suggested to take your vitamins at your largest meal if you can't take them in multiple phases is because your largest meal is the most likely to be well-rounded for more full absorption of the vitamins.

  • 1
    +1 for the second paragraph. You'll probably also absorb more of them total (good), but less at one time (bad for your kidneys etc.) Mar 10, 2011 at 18:11
  • 2
    +1 for the sources. A positive to taking a multivitamin, and in this case all three supplements, at the same time is you do not have to transfer your supplements with you as you go through your day. Mar 10, 2011 at 18:32
  • Also, one of the big functions of vitamin D is to help you absorb calcium, so you want to try to to couple D with calcium intake (through food, multivitamin or whatever).
    – G__
    Mar 10, 2011 at 18:41
  • It also seems there is a co-factor between Vitamin D and Magnesium, as Vitamin D unmasks deficiencies in Magnesium: vitamindcouncil.org/newsletter/…. Mar 10, 2011 at 18:47
  • Also remember that many vitamins/minerals are fat soluble; take them not necessarily with your largest meal but with a meal that contains plenty of fat.
    – J. Win.
    Mar 10, 2011 at 20:08

There are subtleties with different supplements. e.g. I take a lot (45 mg) of zinc daily. Taking so much zinc means I have to take copper at a different tine of day since zinc can inhibit absorption of copper. Also zinc can give a stimulant effect, so it is best not taken at night. Horses for courses.

  • Its also a bad idea to mix zinc and calcium as the compete for absorption iirc. Ironic you mention zinc having a stimulant affect as most people think zinc + magnesium will help you sleep ala ZMA.
    – Adam Gent
    Mar 11, 2011 at 4:39

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