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taking supplements? 







The amount of a substance which enters into circulation when introduced to the body, and is therefore able to have an active effect.

A-Day: engineered for better absorption

A-Day has been Engineered for better absorption

The oral cavity is extremely absorbant

The mouth's lining, known as mucosa, is lined with tightly knit blood vessels right beneath the surface. This allows vitamins to traverse the thin mucosal membrane and slip through the one-cell-thick capillary wall, for direct entry into the bloodstream.

The oral cavity has three distinct zones of absorption: buccal (inside the cheek), sublabial (under the lip), and sublingual (under the tongue). Our gum is engineered to take advantage of all three zones for maximum uptake.

Bypassing the hotile gut environment

Much of the nutrients we swallow are destroyed before reaching the bloodstream, due to the harsh and acidic conditions in the gastrointestinal tract or what is known as the 'first-pass effect of liver metabolism'. 

The A-Day targets the mouth instead, to bypass these challenges.

Relevant journal articles

Bates, C. J., & Heseker, H., (1994). Human Bioavailability of Vitamins, Nutrition Research Reviews, 7, 93-127

Gilhotra RM, Ikram M, Srivastava S, Gilhotra N. A clinical perspective on mucoadhesive buccal drug delivery systems. J Biomed Res. 2014;28(2):81-97. doi:10.7555/JBR.27.20120136

Naimish, A., Vipul, P.P., & Devang, J.P. (2013). Sublingual Delivery: A Promising Approach to Improve Bioavailability.

Narang, N. and Sharma, J. (2011) Sublingual Mucosa as a Route for Systemic Drug Delivery. International Journal of Pharmacy and Pharmaceutical Sciences, 3, 18-22.

Subramanian, P., 2021. Mucoadhesive delivery system: a smart way to improve bioavailability of nutraceuticals. Foods, 10(6), p.1362.


Why we bypass the gut?

Loss of nutrients before they even reach your bloodstream is a well-known problem inside the pharmaceutical industry.

The digestive process often destroys crucial active micronutrients, preventing them from reaching the systemic bloodstream - which has to happen in order for micronutrients to be delievered to the necessary organs. 

Nutrients in conventional supplements must survive the gut and liver

Your stomach's natural acidity and enzymes can make supplements less effective, or outright destroy them. 

There is a rapidly growing research field investigating how to prevent nutrients from being destroyed by gut acidity, emulsification, or metabolising enzymes. 

For instance, B12 is an essential nutrient and common deficiency among vegetarians, but only has an absorption rate of 1-2% via the stomach. There are multiple expensive technologies, such as microencapsulation, trying to offset these common issues.

The A-Day targets the mouth instead to get around these problems.

Your diet can interfere with nutrient uptake

What you eat can have a profound impact on which nutrients your gut absorb, and can make your supplements less effective. 

For example, we know that the phylate from grains and oats inhibits bioavailability of iron and zinc? 

With The A-Day, you do not have to gamify your diet - as our gum is engineered for absorption in the mouth. 

Common medications can reduce absorption

Many take their daily medications and supplements at the same time, not realising that many common drugs can interfere with nutrient uptake in the gut. 

Mohn et al. (2018) have identified some of the most common interactions displayed in the table below, but these are only some of the interactions that have been identified. 
MedicationNutrients affected
NSAIDs Vitamin C, Iron
SSRI antidepressantsVitamin D
Oral contraceptivesVitamin B6 Vitamin B12
BronchodilatorsVitamin D
CorticosteroidsVitamin D
Proton Pump Inhibitors B-Carotene Vitamin B12 Iron
Hypercholesterolemics B-Carotene, D
Anti-hypertensives Thiamin (B9) Zinc
Oral hypoglycemicsVitamin B12 Vitamin D

Relevant journal articles

Bates, C. J., & Heseker, H., (1994). Human Bioavailability of Vitamins, Nutrition Research Reviews, 7, 93-127

Bensky MJ, Ayalon-Dangur I, Ayalon-Dangur R, Naamany E, Gafter-Gvili A, Koren G, Shiber S. Comparison of sublingual vs. intramuscular administration of vitamin B12 for the treatment of patients with vitamin B12 deficiency. Drug Deliv Transl Res. 2019 Jun;9(3):625-630.

Carneiro C, Brito J, Bilreiro C, et al. All about portal vein: a pictorial display to anatomy, variants and physiopathology. Insights Imaging. 2019;10(1):38. Published 2019 Mar 21. doi:10.1186/s13244-019-0716-8

R.J. Wood, BIOAVAILABILITY, Editor(s): Benjamin Caballero, Encyclopedia of Human Nutrition (Second Edition), Elsevier, 2005, Pages 195-201,ISBN, 9780122266942, (

Narang, N. and Sharma, J., 2011. Sublingual mucosa as a route for systemic drug delivery. Int J Pharm Pharm Sci, 3(Suppl 2), pp.18-22.

A-Day is engineered for better bioavailability

Our multi award-winning supplement gum has been developed by a team of Oxford PhD medics, immunologists and biochemists to pack the ultimate nutritional punch. 

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