By Ramneek S. Bhogal DC, DABCI
Deciding whether to deliver a vitamin to the body in pill form or liquid form often depends on biochemistry and physics.
All pill forms of vitamins, including cellulose capsules, take a solid shape that has a chemical structure. So they come with dimensions—size, shape, and rigidity—in addition to the physical properties of how they breakdown in the body. Liquid forms of vitamins don’t have these barriers.
Generally, they’ll be absorbed in the stomach at a different rate than its liquid counterpart. Pill forms can be less than ideal in a variety of circumstances that have to do with the ability to swallow effectively. But those aren’t the only reasons one form might be the preferred delivery system over the other.
The efficacy of the vitamin doesn’t typically depend upon what form it's absorbed in when it reaches the stomach, but the absorption rate is greatly affected by its form. The rate at which a vitamin is absorbed comes down to the physical chemistry of the compound. By and large, a liquid in the stomach will absorb at a much faster rate than solid pill form will. In fact, the body can begin absorbing liquid vitamins before it even reaches the stomach.
That rate—and the reasons for wanting a slower or faster absorption of the vitamin—is a significant factor in whether or not your functional medicine practitioner will recommend a liquid or a pill. If a quicker rate is needed, a liquid form will be preferred, and the surface area and the mechanics of breakdown that accompany the liquid form will actually start to fraction out the nutrients as soon as it’s ingested. With a liquid, the gastrointestinal tract doesn’t have to work as hard to break down and start to process the vitamin.
The dosage of vitamins, and whether liquid or pill form will help achieve the desired outcome, often depends upon the amount of supplementation needed to reach optimal vitamin levels.
If the desired effect is a therapeutic one because a patient is struggling with a particular pathologic presentation, and not just wellness based, dosing may be scaled up. If that is the case, bioavailability may need to be increased, and liquid form may be preferred for two reasons. One, the number of capsules necessary to reach that therapeutic dosing level might not be cost-efficient. And two, it is cumbersome for a patient to take four capsules three times a day. A liquid achieves the dosing level needed more quickly and more efficiently.
Liquids will just partition when they go through the breakdown process in the body, making their bioavailability higher because they’re largely free of the need to actively physically break down. This makes liquid vitamins more available for absorption.
Liquids may have a shorter shelf life than pills because they typically lack the added stabilizers that allow pills to sit on the shelf longer. Hard tablets necessarily come with fillers, bonding agents, and stabilizers to help give it that form. Though they’re shelf stable, these additives come at the cost of bioavailability. Cellulose capsules break down more rapidly than hard tablets, but they still take longer than liquids because of the physical barrier—up to an hour or so. With pill forms of vitamins, there’s also the question of what the added substances are made from. Are they plant-derived or synthetic? Is something being added that the body doesn’t need, and maybe shouldn’t have?
When Liquid Form Is Better
In addition to a preference for a faster absorption rate and a higher dosage, liquid vitamins are generally the preferred form when:
- The patient is a child.
- You need to deliver a higher dosage in a smaller quantity.
- The patient has a pathological presentation like dysphagia.
- A patient has a compromised capacity to swallow for other reasons, such as in spinal cord injuries and neurodegenerative pathologies, if the patient has had a stroke, or if they have Alzheimer’s disease.
- The vitamin absorption fares better with exposure to acids in the stomach because it comes into contact with the stomach acid more freely, such as with iron, calcium, and protein.
- The patient is an adult but for whatever reason has trouble swallowing a pill.
Typically, a dropper is used to deliver the liquid, but a small cup or shot glass may be used as well.
When Pill Form Is Better
Though liquid vitamins have many benefits under certain situations, there are instances in which pills are more likely to be recommended by the practitioner. These include:
- When absorption rates are better for the patient’s needs if they’re sustained slowly over the day, such as with B vitamins, magnesium, and zinc.
- Managing the changing needs of athletes throughout the day.
- When the gut health microbiome benefits associated with slower absorption outweigh the benefits of the rapidity of liquid absorption.
- When therapeutic benefits pose a risk for unpleasant side effects, such as diarrhea, if the vitamin is absorbed too quickly.
Vitamins that come in “pill” form may be hard tablets, cellulose capsules, or powders.
Two major factors that determine whether a liquid or pill form is the right supplement course are the optimal absorption rate and the level of dosing needed to achieve the desired benefit. It’s important to consider the physical properties of the vitamin as well and to ensure that the patient can comfortably manage to take the proper dosage of the preferred form.