Supplement Timing Helps Absorption

By Dr. Shellie L. Rosen, PhD, DOM, L.Ac.

There are best practices for administering supplements in your daily regimen to support nutritional gaps. Read on to identify the best ways to take your supplements to maximize their absorption.

Water-Soluble and Fat-Soluble Vitamins

A vitamin’s mechanism of action and chemical characteristics affect its solubility, digestion role, and desired effect.

Water-soluble vitamins such as vitamin C and most Bs (except for fat-soluble B1) do not require dietary fat for absorption. Therefore, these vitamins can be taken on an empty stomach with a full glass of water. Vitamin C inhibits B12 absorption; a two-hour separation helps.

Fat-soluble vitamins such as vitamins A, D, E, K, and K2 do best when accompanied with food, especially fats, to assist their absorption. However, avoid dairy fat with Vitamin D3/K2 (which helps remove excess calcium from the body) to avoid binding calcium with the vitamins during digestion. In addition, herbals and greens often carry components best paired with a small amount of fat to absorb phytonutrients, including carotenoids and chlorophyll.

Digestive Helpers

Before Eating: Digestive supplements such as apple cider vinegar or betaine hydrochloride (HCL) increase stomach acids or digestive enzymes to break down and digest food.

After Eating: Purified bile salts help with later stages of digestion and can decrease stomach acids. Probiotics are best taken at night when they can populate the gastrointestinal system.


Minerals, such as electrolytes or calcium, need acid for absorption, so it is best to take them on an empty stomach when stomach acid is higher. Magnesium and calcium compete for absorption during digestion. Iron, zinc, and copper also block one another in digestion. Therefore, a two-hour separation window when taking these minerals provides the best outcome. Iron is best on an empty stomach or with vitamin C (perhaps a citrus juice); caffeine and calcium interfere with absorption. Consider taking calcium between meals because it may decrease the benefits of antioxidants in multivitamins. (For more detail on magnesium, D3/K2, locate the December 2021 issue of Prime Time online.)


Consider supplements that may interfere with medications such as omega-3 fatty acids, which affect blood thinners, and thyroid medications. Many COVID-19 long-haulers take blood thinners and need to consider new supplement protocols. Your pharmacist can check your supplements for drug interactions if you offer them a list.

A multivitamin is best with a meal to prevent stomach upset. Take the supplements you need and enjoy most nutrients through fresh, non-processed living foods. Take occasional breaks from non-essential supplements to gauge your continued need for them. Rely on the outdoors for health-giving airborne probiotics and sunshine any time of day. Abundant Blessings! Shellie L. Rosen, PhD, DOM, L.Ac.

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