Guide · Oct 12, 2026
Do Supplements Break a Fast? 30 Common Supplements Checked
Most capsules and tablets carry almost no calories. Gummies, protein powders and amino acids are where fasts actually get broken.
By the Ping Diet editorial team · Last updated
_By the PingDiet Editorial Team · Last updated October 12, 2026_
Short answer: Most plain capsules and tablets, such as a multivitamin, magnesium or creatine, contain so few calories that they don't break a fast. Three groups usually do: gummies and chewables (they contain sugar), anything with protein or amino acids (collagen, whey, BCAAs) and oil-based or powdered drinks with added carbohydrate. A separate question is whether a supplement works or sits well on an empty stomach; several don't.
How we judged each supplement
We looked at two things. First, energy: does a typical serving supply meaningful calories, sugar or protein? Second, absorption and tolerance: is the nutrient fat-soluble or known to upset an empty stomach? Nutrient facts come from the NIH Office of Dietary Supplements (ODS) fact sheets [1]; serving calories are typical label values and vary by brand, so check yours.
"Breaks a fast" here means it adds meaningful calories or protein. It is not a statement that the supplement is useful or needed. This table is not medical advice; ask your clinician before starting or timing any supplement, especially alongside medication.
The table
| # | Supplement | Typical calories/serving | Breaks a fast? | Best timing note |
|---|---|---|---|---|
| 1 | Multivitamin tablet | 0–5 | No | Often better with food; can cause nausea when empty [1] |
| 2 | Multivitamin gummy | 15–30 (sugar) | Yes | Take in your eating window |
| 3 | Vitamin D (capsule) | ~0–5 | No | Absorbed better with a meal containing fat [2] |
| 4 | Vitamin D in oil softgel | ~5–10 | Minimal | With a meal for absorption |
| 5 | Vitamin C | 0 | No | High doses may upset the stomach |
| 6 | B-complex | 0 | No | Some people get nausea when empty |
| 7 | Vitamin B12 | 0 | No | Fine anytime |
| 8 | Vitamin K2 | ~0 | No | Fat-soluble; with food |
| 9 | Vitamin E | ~0–10 | Minimal | Fat-soluble; with food |
| 10 | Magnesium (glycinate, citrate) capsule | 0 | No | Citrate can loosen stools |
| 11 | Magnesium gummy | 10–30 | Yes | Eating window |
| 12 | Zinc | 0 | No | Commonly causes nausea on an empty stomach [3] |
| 13 | Iron | 0 | No | Absorbed best empty but often upsets the stomach; follow your clinician [4] |
| 14 | Calcium carbonate | 0 | No | Needs stomach acid; take with food [5] |
| 15 | Potassium (food-level doses) | 0 | No | See our electrolytes guide; high-dose pills need medical advice |
| 16 | Electrolyte powder, unsweetened | 0–10 | No | Useful on longer fasts |
| 17 | Electrolyte drink with sugar | 20–80+ | Yes | Read the label |
| 18 | Creatine monohydrate | 0 | No | Timing matters little [6] |
| 19 | Fish oil softgel (1 g) | ~9–10 | Minimal | Better tolerated with a meal |
| 20 | Fish oil or omega-3 gummy | 15–40 | Yes | Eating window |
| 21 | Collagen peptides (10 g) | ~35–40 (protein) | Yes | Eating window |
| 22 | Whey protein scoop | 100–130 | Yes | It's a Ping |
| 23 | BCAAs / EAAs | 0–40, plus leucine | Yes | Amino acids, especially leucine, stimulate insulin and muscle-growth signaling [7] |
| 24 | Probiotic capsule | ~0 | No | Strain-dependent; follow the label |
| 25 | Psyllium / fiber powder | 15–30 | Yes, mildly | Some carbohydrate; with water in your window |
| 26 | Apple cider vinegar liquid (1 tbsp) | ~3 | No | Dilute it; acid can harm enamel |
| 27 | Apple cider vinegar gummy | 15–20 (sugar) | Yes | Eating window |
| 28 | Melatonin tablet | 0 | No | Bedtime only |
| 29 | Ashwagandha capsule | 0 | No | Not for pregnancy; can interact with thyroid medication [8] |
| 30 | Turmeric / curcumin | 0 | No | Better absorbed with fat; can upset the stomach |
Why gummies are the big exception
Gummies are candy-format supplements. Most use sugar or glucose syrup to hold their shape, typically 2–4 g of sugar per serving. That is small, but it is carbohydrate that raises blood sugar, which is exactly what a fasting window is meant to avoid. If you take gummy vitamins, put them in your eating window.
Protein and amino acids: the quiet fast-breakers
Collagen and BCAA drinks are marketed as "fasting friendly," but they deliver amino acids. Leucine in particular activates mTOR and stimulates insulin secretion [7], the opposite of the low-insulin state fasting produces. If you train fasted and want amino acids, that's a reasonable choice, but count it as ending the fast.
Fat-soluble vitamins and empty stomachs
Vitamins A, D, E and K dissolve in fat. Taking vitamin D with the largest meal of the day raised blood levels by about 50% in one study compared with taking it without food [2]. So even when a supplement doesn't break a fast, the fasting window may be the worst time to take it.
Sources
- NIH Office of Dietary Supplements. Dietary Supplement Fact Sheets. https://ods.od.nih.gov/factsheets/list-all/
- Mulligan GB, Licata A. Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D. J Bone Miner Res. 2010;25(4):928-930.
- NIH ODS. Zinc: Fact Sheet for Health Professionals.
- NIH ODS. Iron: Fact Sheet for Health Professionals.
- NIH ODS. Calcium: Fact Sheet for Health Professionals.
- Kreider RB, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation. J Int Soc Sports Nutr. 2017;14:18.
- Kalogeropoulou D, et al. Leucine, when ingested with glucose, synergistically stimulates insulin secretion and lowers blood glucose. Metabolism. 2008;57(12):1747-1752.
- NIH ODS. Ashwagandha: Fact Sheet for Health Professionals.
Frequently asked questions
Do vitamins break a fast?
Plain tablets and capsules don't, since they have essentially no calories. Gummy vitamins do, because they contain sugar.
Does creatine break a fast?
No. Creatine monohydrate has no calories and doesn't raise insulin by itself.
Does collagen break a fast?
Yes. A 10 g scoop is about 35–40 calories of protein.
Do BCAAs break a fast?
Yes. Amino acids, especially leucine, trigger insulin release and muscle-building signals.
Should I take my supplements during the fast or with food?
Most fat-soluble vitamins, zinc, calcium carbonate and fish oil are better with a meal. Water-soluble vitamins and creatine can be taken anytime. Ask your clinician about iron and any prescription timing.