I recently fell ill with a cold, and began to take a vitamin C capsule each day to help my immune system. When I noticed no change in my condition, I began to incorporate an abundance of citrus into my diet instead of taking the capsules. When I ate the citrus my condition began to improve markedly.

The ingredients listed by the vitamin manufacturer are:

  • Ascorbic Cellulose Gel
  • Hydroxypropyl Cellulose
  • Croscarmellose Sodium
  • Stearic Acid
  • Magnesium Stearate
  • Silicon Dioxide

Not excluding the possibility of coincidence, I was was intrigued. Has evidence been published to suggest that nutrients in whole foods like vitamin C in citrus fruits are more readily utilized in the body than nutrients in vitamin capsules?

  • 2
    $\begingroup$ That's a coincidence. If you had eaten the fruits first and the pills then, you would probably see it the other way round. The body does not decide between vitamins coming from fruit or pills. $\endgroup$ – Chris Feb 26 '16 at 14:40
  • $\begingroup$ I concluded that that was most likely, though the hypothesis occurred to me that whole foods contain secondary nutrients that encourage uptake or utility of primary nutrients. I'm not making any assumptions, just asking if anyone has tested that hypothesis. $\endgroup$ – Andrew Feb 26 '16 at 16:39
  • $\begingroup$ Colds generally last a limited amount of time so your recovery probably has more to do with your body's natural response than any vitamins, synthetic or food-based. $\endgroup$ – augurar Mar 22 '16 at 6:41
  • $\begingroup$ Like the question, but, as you and others have already pointed out, your sickness scenario is likely due to coincidence. $\endgroup$ – theforestecologist Mar 23 '16 at 4:57

The answer probably varies for different nutrients. An informal article by ConsumerLab.com indicates that many vitamins are better absorbed from natural sources, but a few are actually more readily absorbed from supplements.

Looking at Vitamin C specifically, a 2013 review article by Carr and Vissers concluded as follows (emphasis mine):

Overall, a majority of animal studies have shown differences in the comparative bioavailability of synthetic versus food-derived vitamin C, or vitamin C in the presence of isolated bioflavonoids, although the results varied depending on the animal model, study design and body compartments measured. In contrast, all steady state comparative bioavailability studies in humans have shown no differences between synthetic and natural vitamin C, regardless of the subject population, study design or intervention used. Some pharmacokinetic studies in humans have shown transient and small comparative differences between synthetic and natural vitamin C, although these differences are likely to have minimal physiological impact.

In other words, with vitamin C natural and synthetic sources appear to be equally bioavailable for humans. The authors do note that "Although synthetic and food-derived vitamin C appear to be equally bioavailable in humans, ingesting vitamin C as part of a whole food is considered preferable because of the concomitant consumption of numerous other macro- and micronutrients and phytochemicals, which will confer additional health benefits."


  • Carr, Anitra C.; Vissers, Margreet C. M. (2013). "Synthetic or food-derived vitamin C—Are they equally bioavailable?". Nutrients 11 (5). pp. 4284–4304. doi:10.3390/nu5114284. PMC 3847730.

This is not a coincidence. Food-sourced vitamins are prized because of being in bio-available form, soluble and absorbable. The only way to make a vitamin more absorbable is to deliver it elementally, with no digestion required at all.

The best absorption rates are through sublingual administration of elemental sprays, no additives,no fillers, nothing except what your body needs for maintenance and repairs. There is a 2011 review of research here:


  • 1
    $\begingroup$ I don't think IJPLS is a real peer-reviewed journal, they are published by a sketchy open-access publisher and they list a fake impact factor on their website. $\endgroup$ – augurar Mar 22 '16 at 6:40

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