Do you take a vitamin supplement? About 52 percent of American adults take a vitamin supplement according to data from over 37,000 people in a 2016 study (1).
Researchers compared data on vitamin supplements from 1999-2000 compared to 2011-2012. While the amount of adults taking supplements didn’t change significantly between these years, the type of supplement people take did change.
There was a significantly lower number of adults taking multi-vitamins in 2011-2012 compared to 1999-2000 (31% compared to 37%, respectively).
However, the amount of adults taking vitamin D and omega 3 supplements increased significantly in 2011-2012 compared to 1999-2000.
Whether you should take a supplement or not depends on many factors and should be under the recommendation of your healthcare team. If you do take vitamin(s) supplement, when you take them can influence how much of the supplement your body absorbs.
Here are some important factors to consider when you should take vitamins to optimize the absorption.
Keep in mind the way we absorb nutrients is different from food compared to supplements, and there are MANY factors that influence our digestion and absorption of nutrients.
Should you take a vitamin supplement?
Health experts are divided on potential benefits of taking vitamin/mineral supplements. In general, most experts agree taking a multivitamin that provides about 100% RDA intake does not harm health.
Before taking any supplement, it is recommended to consult your healthcare team.
Certain medical conditions or nutritional deficiencies warrant supplement intake. However, supplements can interfere with absorption of medication, other supplements and even other nutrients when taken with food.
Some research studies (2) have shown multi-vitamin/mineral supplement do not lower risk for overall mortality or other chronic health conditions. Taking a supplement is not a substitute for following a healthy diet and lifestyle.
More research is needed for clarifying how different supplements affect health.
When should you take prenatal vitamin?
Prenatal vitamins are designed to provide nutrients that are needed even more so during pregnancy. They can be taken even before you are pregnant if you are trying to conceive.
Mayo Clinic (3) suggests taking a prenatal vitamin with a meal/snack or before bed time to lower risk of nausea.
The iron in prenatal vitamins may cause nausea on an empty stomach, and some women may feel queasy if prenatal is not taken with food.
If you have any changes in bowel movements or other symptoms after taking a prenatal vitamin, consult your doctor.
There may be another prenatal vitamin with varying nutrients that may be better for your body.
When should you take a multi-vitamin?
If you are taking any medications, follow the advice from your health practitioner for advice on taking supplements with your medications.
In general, multivitamins provide 100% RDA or less of vitamins and/or minerals. The best time to take a multivitamin is the easiest time for you every day whether it’s right away when you wake up or before you go to bed.
If you notice any stomach discomfort from taking a multi on an empty stomach, take it with a meal.
If you are taking other supplements such as higher doses of minerals, Consumer Lab (4) recommends spreading out your supplements.
Take your multi at a different time of day than other supplements to increase absorption for all nutrients.
When should you take individual vitamin supplements?
Individual vitamin or mineral supplements can range in dosage which can vary the impact of absorption.
In general, if you are taking one nutrient supplement, take it at a different time than other supplements. Spread them out through the day.
Fat soluble vitamins
The fat soluble vitamins are vitamins A,D,E and K. Taking these supplements with food can increase absorption of these nutrients, especially when a fat source is included in the meal.
A 2005 study (5) found adding avocado or avocado oil to a salad significantly increased absorption of beta carotene (a pre-form of vitamin A). It also increased absorption of other antioxidants like lutein and alpha carotene.
A 2000 review (6) on carotenoids suggests the amount of fat needed to absorb carotenoids (and probably other fat soluble vitamins) is around 3-5 grams per meal.
In other words, you don’t need to dose a meal in oil to better absorb fat soluble vitamins in a meal.
Vitamin C and B vitamins
Water soluble vitamins, C and B vitamins, are absorbed with water and don’t need fat for absorption. In general, the body doesn’t store these nutrients like it stores fat soluble vitamins.
If you are taking a B or C vitamin, you can take it on an empty stomach or before a meal.
When should you take mineral supplements?
Mineral supplements, especially large doses, are vulnerable to changes in absorption. For example, the absorption of calcium, zinc, magnesium and iron use similar transporters in the intestine and compete for absorption.
Therefore, taking these single nutrient supplements should be taken at different times of the day for optimal uptake.
Whether you should take these supplements with food may vary depending on individual health concerns.
In general, taking single mineral supplements with food may lower risk for digestive discomfort.
American Bone Health (7) also suggests excessive salt can interfere with calcium absorption. Therefore, lowering salt in general in your diet and taking calcium with a lower salt meal can optimize absorption.
Considerations for taking vitamins
Keep in mind the body is a complex system, and absorption of nutrients is influenced by many factors. More supplements are not always better, and sometimes supplements may even have negative health consequences.
For example, one study (8) found those at high risk for lung cancer, such as smokers, may have an increased risk for lung cancer when taking beta carotene supplement.
This is a surprising finding as a diet rich in fruits and vegetables (and beta carotene) is associated with a lowered risk for cancer. However, the impact a nutrient has on health is different when absorbed from whole foods compared to concentrated supplements.
If you are wondering if you should take supplements, consult your healthcare team for individualized recommendations.