How Long Does It Take for Vitamins To Work?

Aug 15, 2023 FAQs 7 MIN

How Long Does It Take for Vitamins To Work?

Quick Scoop

  • Vitamins are absorbed in our digestive system, and the process can vary depending on the type of vitamin.
  • Factors that affect vitamin effectiveness include your current vitamin levels, the type and form of the vitamin, diet, age, consistency, and more.
  • You can create an effective vitamin regimen by choosing the right vitamins, making a daily schedule, and consulting with your healthcare provider for personalized recommendations.

If you’re starting a vitamin regimen, you may be wondering how long does it take for vitamins to work? It can take anywhere from several weeks to a few months of consistently taking a vitamin or mineral supplement to see noticeable changes, depending on several factors.

Some of these factors include your current vitamin levels, the type of vitamins you’re taking, and how bioavailable (absorbable) the specific product is.

Keep reading to understand how vitamins are absorbed in the body, the factors that determine their effectiveness, and how to create a consistent vitamin routine that works for you.

How Are Vitamins Absorbed By Our Body?

Vitamins are absorbed in the body through the digestive system, in a similar manner as food. When you take your vitamin supplement, it passes through the stomach into the small intestine where it is broken down and absorbed into the bloodstream.[1]

This process of vitamin absorption can vary depending on the type of vitamin and whether it is water-soluble or fat-soluble. Some vitamins, minerals or foods in our diet can also affect vitamin or mineral absorption for better or for worse. For example, fat soluble vitamins like Vitamin D require fat in your meal to be absorbed. Vitamin C aids in iron absorption. Conversely, phytic acid in foods like beans, whole grains, nuts and seeds inhibit nonheme Iron absorption.†

Our gut probiotic bacteria play a large role in not only our gut health but in supporting vitamin digestion. How effectively your vitamins are absorbed is dependent on several factors including the quality of the vitamin you are taking.[2]†

Learn more: Vitamins That Shouldn’t Be Taken Together

Factors That Affect Vitamin Efficacy

If you’re investing in vitamin supplements, you’ll want to make sure you’re getting the full benefits from taking them. To answer the question “How long does it take for vitamins to work?” it’s important to know the top factors that influence their effectiveness.

Current Vitamin Levels

If certain vitamin levels in your blood are low, such as Vitamin D, you will likely experience noticeable benefits sooner. The exact timeframe of how long it takes for the vitamins to work can vary depending on the person, but in general, it will happen faster if you truly need to correct a vitamin deficiency.

You will know if the vitamins are working if you see an improvement in your bloodwork or in your overall wellness.

Type of Vitamin

As mentioned earlier, there are two types of vitamins based on how they are absorbed: water-soluble and fat-soluble vitamins.

Water-soluble vitamins include the B Vitamins and C. These are absorbed directly by the cells in the small intestine and then released into the bloodstream. Water-soluble vitamins are not stored in your body and any excess amounts are removed daily in your urine.

Fat-soluble vitamins include Vitamins A, D, E, and K, and require fat to be absorbed. They should be taken alongside a fat source such as nuts, nut butter, avocados, seeds, or olive oil for proper absorption.

Once they are inside the small intestine, fat-soluble vitamins are combined with dietary fat and released into the lymphatic system, which eventually drains into the bloodstream for energy. Excess amounts of these vitamins are stored in the liver and fat tissue.


Certain dietary factors can either positively or negatively affect vitamin absorption.

If your diet is lacking adequate fat, this can decrease absorption of the fat-soluble Vitamins A, D, E, and K. On the other hand, certain nutrients in the diet can increase vitamin supplement absorption such as Vitamin D and Calcium and Vitamin C and Iron. Research has shown Vitamin D may help improve Calcium absorption and Vitamin C may support Iron absorption.[3]†

If you’re taking vitamin supplements, eating foods high in vitamins that aid in their absorption like Vitamin C, Calcium, and dietary fat can help.

Learn more: Vitamins That Complement Each Other


Research shows the ability to absorb certain nutrients declines with age. Certain B Vitamins like B12, Vitamin D and Calcium are nutrients that are specifically affected by changes in the way we can absorb these nutrients as we get older.[4]

This is why as you get older it becomes even more important to prioritize nutritious foods in the diet and supplement as needed, as advised by your healthcare provider, to support optimal health.

Learn more:  7 Best Healthy Foods To Incorporate Into Your Diet


It’s not always easy to remember to take your vitamins. But in order to reap the maximum benefits and bridge any nutrient gaps that may be missing from your daily diet, your vitamins need to be taken every day.

If you’re frequently forgetting your daily dose or are sporadic with your vitamin routine, chances are it’s taking longer to experience the benefits.

It is especially important to replenish your water-soluble B Vitamins and C daily, as they are constantly being excreted from the body.


The bioavailability of a vitamin is the amount that is able to be consumed and utilized by the body. The higher the bioavailability, the better, because this means your body will soak up a larger amount of it and put it to good use.

Several factors can affect the bioavailability of a vitamin including the form of the vitamin and the timing of when you are taking it. For example, some vitamins can be taken on an empty stomach, while others, such as fat-soluble vitamins, are best taken with food. 

Learn more:  When Is The Best Time To Take Vitamins And Supplements?

How To Create An Effective Vitamin Regimen

If you’re wondering how long does it take for vitamins to work, it starts with creating a consistent daily routine of choosing the right vitamins for your needs.

Choose the Right Vitamins

The first step is choosing quality vitamins from a reputable brand. Nature Made® vitamins are the number one pharmacist recommended vitamins & supplements brand and carry several supplements that are third-party tested for purity and quality.

We also offer highly bioavailable forms of vitamins and minerals such as our Magnesium Glycinate, Magnesium Citrate and Folic Acid supplements.

Make a Daily Schedule

Create a daily schedule of when you will take your vitamins. Stacking this habit with another habit you have already in place can make it easier to remember.

For example, you can take your vitamins every morning with breakfast, or with your evening meal before you’re winding down for bed. Another tip is to organize your vitamins and supplements where you can see them such as on your kitchen counter.

Making note of any vitamins that need to be taken with food, like the fat-soluble vitamins, will help to enhance their effectiveness.

Talk with a Healthcare Provider

Before starting a new vitamin regimen, speak to your healthcare provider for personalized recommendations. Your doctor can provide individualized vitamin supplement suggestions based on your diet, vitamin levels, medical history, and lifestyle.

They can also help track your vitamin levels to ensure they are going in the right direction.

Once you have a plan in place, look no further than our Nature Made® quality vitamin supplement line to support your health and wellness goals.†

Get more information about vitamins:

Follow @NatureMadeVitamins on Instagram for new product news, healthy tips, and more.

*Based on a survey of pharmacists who recommend branded vitamins and supplements.

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.


  1. Ofoedu CE, Iwouno JO, Ofoedu EO, Ogueke CC, Igwe VS, Agunwah IM, Ofoedum AF, Chacha JS, Muobike OP, Agunbiade AO, Njoku NE, Nwakaudu AA, Odimegwu NE, Ndukauba OE, Ogbonna CU, Naibaho J, Korus M, Okpala COR. Revisiting food-sourced vitamins for consumer diet and health needs: a perspective review, from vitamin classification, metabolic functions, absorption, utilization, to balancing nutritional requirements. PeerJ. 2021 Sep 1;9:e11940. doi: 10.7717/peerj.11940. PMID: 34557342; PMCID: PMC8418216.
  2. Maynard, C., Weinkove, D. Bacteria increase host micronutrient availability: mechanisms revealed by studies in C. elegans. Genes Nutr 15, 4 (2020).
  3. Khazai N, Judd SE, Tangpricha V. Calcium and vitamin D: skeletal and extraskeletal health. Curr Rheumatol Rep. 2008 Apr;10(2):110-7. doi: 10.1007/s11926-008-0020-y. PMID: 18460265; PMCID: PMC2669834.
  4. Veldurthy, V., Wei, R., Oz, L. et al. Vitamin D, calcium homeostasis and aging. Bone Res 4, 16041 (2016).


Melissa Mitri, MS, RD

NatureMade Contributor

Melissa Mitri, RD is a seasoned dietitian and health writer. She specializes in helping women move away from restrictive habits that lead to vicious yo-yo weight cycles. Melissa enjoys writing about health, nutrition, and fitness with the goal of simplifying complex health topics for the reader. Find out more about Melissa at

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Sandra Zagorin, MS, RD

Science and Health Educator

As a member of the Medical and Scientific Communications team, Sandra educates healthcare professionals and consumers on nutrition, supplements, and related health concerns. Prior to joining Pharmavite, Sandra worked as a clinical dietitian at University of Chicago Medicine in the inpatient and outpatient settings. Sandra received her Bachelor of Science degree in Nutritional Science, with minors in Spanish and Chemistry from the University of Arizona in Tucson, AZ. She earned her Master of Science degree in Clinical Nutrition from RUSH University in Chicago, IL. As part of her Master’s program, Sandra performed research on physical activity participation and correlates in urban Hispanic women.

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