When is the best time to take magnesium before or after food?

The meal-clock walked, before, during and after, and what each position actually changes

Before or after food is a question about the meal-clock, the minutes around a plate, and walking the three positions shows how little they change. Before, the twenty-minutes-before position: it comes from digestive enzymes and some medicines that need an empty stomach to work or to avoid food binding, and magnesium has no such need, the mineral being absorbed along the small intestine on a saturable transporter that a meal does not block, so twenty minutes before a meal is a fasted dose in all but name, fine for a bisglycinate reader whose stomach does not object and pointless as a strategy, the empty-stomach page's finding. During, with the meal: the section's direction, for comfort, since a fasted dose makes a minority queasy, for transit, since a meal slows gastric emptying and lengthens the absorption window so that fed absorption at least equals fasted, and for the anchor, since the plate is the fixed point a daily habit survives on, the with-food page's three reasons. After, just after or within the hour: identical to during in every respect that matters, the meal still in the stomach slowing transit, the comfort the same, the anchor a minute later, so a reader who forgets the capsule until the plate is cleared has lost nothing by taking it then. The three positions walked, the honest finding is that with or after beats before by a small margin of comfort and transit, that the margin is small, and that the position on the meal-clock is decided by whichever the reader will keep, the evening meal being the section's anchor for exactly that reason.

The one strict clock, which is a medicine's and not magnesium's, and the meal-clock filed

The one strict clock on this page belongs to a medicine, not to magnesium, and it overrides the meal-clock entirely for the reader it concerns. Levothyroxine is taken fasted, typically thirty to sixty minutes before breakfast, and its absorption is reduced by magnesium, calcium and iron taken near it, the usual guidance being a gap of about four hours, so for that reader the question of magnesium before or after breakfast has one answer, neither, the magnesium moving to the evening meal, hours away; the bisphosphonates, taken fasted with water and a wait before food, carry the same rule; and the tetracycline and quinolone antibiotics are spaced by hours in either direction for their course. Those are clocks with a mechanism and a consequence, and the meal-clock for magnesium alone has neither. The meal-clock filed: take magnesium with the meal or just after it, the difference between the two being nothing and the difference from a fasted twenty-minutes-before being comfort and a little transit, choose the meal you will keep, the evening for most or split between breakfast and dinner, and, if you take a fasted morning medicine, keep magnesium out of that morning altogether and at the evening plate, the worked example directing two capsules with the evening meal and being equally content a few minutes after it, 300mg elemental at 80% NRV, £19.99 for 90 days at 22p.

The verdict, with or after, and never near a fasted medicine

When is the best time to take magnesium before or after food: with the meal or just after it, the two being identical and both beating a fasted twenty-minutes-before by a small margin of comfort and transit, the before position being digestive-aid folklore with no magnesium reason, the meal chosen being the one the reader will keep, and the only strict clock belonging to fasted medicines, levothyroxine and the bisphosphonates, from which magnesium keeps hours away at the evening plate. Directed with the meal and content just after it: Futuro Labs Magnesium Glycinate, two capsules with the evening meal, 300mg elemental at 80% NRV, £19.99 for 90 days at 22p a day.

What to check on the label

Questions people also ask

Should magnesium be taken before or after eating?

With the meal or just after it, the two being identical for comfort, transit and the habit's anchor, and both slightly better than a fasted dose twenty minutes before, which is folklore borrowed from digestive enzymes.

Does taking magnesium after food reduce absorption?

No: a meal slows transit and lengthens the absorption window, so fed absorption at least equals fasted, and a dose taken just after a plate is cleared absorbs as well as one taken with it.

Is there a reason to take magnesium twenty minutes before a meal?

None from the mineral: that position is an empty-stomach dose in all but name, fine for a bisglycinate reader whose stomach allows it and pointless as a strategy.

Which meal is best for magnesium?

The one you will keep: the evening meal for most as the most reliable anchor, or the dose split between breakfast and the evening meal for a reader who prefers smaller amounts.

I take thyroid medication before breakfast, when do I take magnesium?

At the evening meal, hours away: levothyroxine's absorption is reduced by magnesium near it, the usual guidance being a four-hour gap, so the morning is the medicine's and the evening is the mineral's.

Sources

1. The magnesium absorption literature: fractional absorption of magnesium falls as the dose rises, so the same daily amount taken in divided doses is absorbed at a higher fraction and with less osmotic laxative effect than a single large dose. PubMed record
2. The magnesium and medicines literature: magnesium supplements reduce absorption of tetracycline and quinolone antibiotics, bisphosphonates and levothyroxine when taken together and are spaced from them, while proton-pump inhibitors and some diuretics lower magnesium status, a reason for medical advice in either direction. PubMed record
3. The habit formation literature: anchoring a new behaviour to an existing daily routine is the best-documented adherence strategy, with consistency outperforming timing choices. PubMed record
4. The GB claims register, magnesium entries: magnesium contributes to a reduction of tiredness and fatigue, normal psychological function, normal nervous system function, normal muscle function and electrolyte balance, among others. https://www.gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register

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