We spend a lot of time cooking quinoa, throwing back green juice, and just generally trying to optimize our diet.

But even the seemingly healthiest eating habits may not deliver all the nutrients you need. Why?

“Our poor food supply,” says nutritionist (and Brooklyn Bridge Boot Camp founder) Ariane Hundt, citing depleted soil, pesticides, and harvesting foods early to ship them.

Not to mention lifestyle issues like desk jobs, which steal your vitamin D.

So is your multivitamin enough to cover these losses? To determine your ideal daily dose, we asked a handful of experts.

Wash down their seven rules for taking supplements with lots of water.

1. Get It From Food First

This may be obvious, but it’s worth repeating.

“Supplements are meant to do just that—supplement—your diet, and in no way replace eating healthy foods,” says Keri Glassman, celeb nutritionist and founder of Nutritious Life.

“Our bodies are designed to reap all of our nutrients from the food we eat from a healthy varied diet.”

All of the experts we asked agreed. Double cheeseburgers with a perfect regimen of pills and powders just won’t cut it.

2. Make Sure You’re Absorbing Nutrients

Even if you’re eating well and taking supplements, you may not be taking in as many nutrients as you’d think.

Drinking coffee, for example, inhibits absorption of iron and calcium, and vitamin D absorption depends on your calcium levels.

You should take supplements with a meal for maximum absorption, says Ariane Hundt.

3. Consider If You’re Getting Enough

Celeb nutritionist Oz Garcia points out that “the government’s Recommended Daily Allowances (RDAs) for vitamins and minerals is typically below what people truly need.”

So you may need to take a higher dose than what’s on a label to get what you need.

Don’t worry: As long as the supplement is water soluble, your body will just excrete what it doesn’t need. (Exceptions: vitamin D and iron can be toxic in high doses.)

4. Go For Top-Shelf Supplements

Just like organic, locally-grown vegetables are better than shipped-in pesticide-laden ones, high-quality supplements have more to offer.

“You should take a daily multivitamin that’s food-based—made from organic substances, not synthetic,” says Hundt.

She recommends avoiding drugstore brands like One-A-Day or Centrum and instead reaching for high-quality vitamins such as New Chapter, Bluebonnet, or Solgar.

“Your body absorbs the ingredients more readily and you don’t end up overdosing or excreting excess,” she explains.

5. Swallow Them Whole

Supplement form is crucial, say experts.

“Look for multivitamins in easily absorbed, capsule form with an enteric coating versus harder-to-digest tablet versions,” says integrative physician Dr. Frank Lipman. 

Skip liquid supplements. Though they’re easier to swallow for some, they’re often deficient in enzymes that aid in vitamin absorption.

7. Take These, If Nothing Else

Keeping all of the previous rules in mind, there were a few supplements that our nutrition panel kept coming back to—starting with a quality multivitamin.

“Multivitamins are very beneficial as a foundation,” says Oz Garcia.

Then, consider these: vitamin D (especially if you live in New York or any other sun-deprived state), an omega-3 boost like fish or flaxseed oil, vitamin B12 if you’re a vegan, plus a probiotic, and calcium.

Everyone also agrees you need a load of antioxidants, but you’ll do better if you can get them from bright, fresh fruits and veggies.

More Reading:

Is it cheating (and less nutritious) if you get your greens from a powder?

Why your tea may not be as healthy as you think it is (and how to fix that)

Maca: Why this superfood has us screaming (in the bedroom)