NutriStack
Vitamin B5 and Vitamin B7, timing-sensitive.
Both vitamins ride the same SMVT carrier in the gut and at the cellular level, so they are direct competitive substrates. Cell and transfected-cell studies confirm pantothenic acid competitively inhibits biotin uptake (and vice versa), but under ordinary dietary and physiological intakes the inhibition is quantitatively minor. The interaction becomes theoretically more relevant only at the gram-level mega-doses sometimes found in standalone supplements, where one vitamin in large excess could blunt uptake of the other taken at the same moment.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Vitamin B5 and Vitamin B7
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Moderate
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored timing-sensitive row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Timing Sensitive · Moderate evidence
Timing Sensitive
What is happening. Both vitamins ride the same SMVT carrier in the gut and at the cellular level, so they are direct competitive substrates. Cell and transfected-cell studies confirm pantothenic acid competitively inhibits biotin uptake (and vice versa), but under ordinary dietary and physiological intakes the inhibition is quantitatively minor. The interaction becomes theoretically more relevant only at the gram-level mega-doses sometimes found in standalone supplements, where one vitamin in large excess could blunt uptake of the other taken at the same moment.
Mechanism. Biotin (vitamin B7) and pantothenic acid (vitamin B5) are both substrates of the same intestinal and cellular carrier, the human sodium-dependent multivitamin transporter (hSMVT, encoded by SLC5A6). Because they share this single transport route, the two vitamins compete for uptake: a large surplus of one can partially saturate the transporter and modestly reduce absorption of the other. The competition is reciprocal at the transporter level.
Recommendation. No avoidance is needed for normal multivitamin-level intakes (biotin a few hundred mcg, B5 a few to tens of mg), where both are absorbed adequately together. If you are taking high standalone doses of one (for example, biotin 5,000 to 10,000 mcg for hair and nails, or pantothenic acid 500 mg or more), separate the two by about 2 to 3 hours to avoid same-dose transporter competition and to maximize uptake of each.
Minimum separation. 2 to 3 hours when either is taken at high (gram-level or several-hundred-mg) doses
Sources (3)
- Linus Pauling Institute, Oregon State University, Micronutrient Information Center: Biotin (nutrient interactions section noting that pantothenic acid and lipoic acid compete with biotin for the sodium-dependent multivitamin transporter)
- Reviews on cellular and molecular aspects of human intestinal biotin absorption describing the SMVT system shared by biotin, pantothenic acid, and lipoate
- Studies on the sodium-dependent multivitamin transporter (SLC5A6) showing competitive uptake of biotin and pantothenic acid, where a surplus of one substrate can saturate the transporter and reduce uptake of the others
Stack Score
How this pair moves the number.
Effect on the composite score
If both Vitamin B5 and Vitamin B7 are in the same stack, this pair applies −5 to your Stack Score (per scored timing-sensitive row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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