Which scientific studies does First Day look at?Updated 8 days ago

Science guides every formula

Research plays a key role in how we select ingredients and design our products.

Our team reviews a wide range of peer-reviewed studies, clinical research, and nutrition data to understand how vitamins and minerals work in the body.

What we focus on

We look at research across areas like:

• Nutrient absorption and bioavailability
• Micronutrient function and daily nutrition
• Diet patterns and real-world nutrition habits

This helps us build formulas that are balanced, thoughtful, and designed for everyday use.

How this shows up in our products

• Ingredient forms commonly used in research
• Nutrients selected to work well together
• Formulas designed to complement a daily diet

Examples of research areas we review

Here are a few types of studies that help inform our approach:

Nutrient absorption and bioavailability

• Studies comparing different forms of vitamins like folate, B12, and Vitamin E
• Research on how nutrients are absorbed from foods and supplements

Micronutrient function

• Research on how vitamins like Vitamin C, B vitamins, and Vitamin K support normal body functions
• Studies on commonly used nutrient forms such as P5P and methylcobalamin

Diet and nutrition patterns

• Public health research on fruit and vegetable intake
• Studies on nutrient intake across different populations

Why this matters

• Helps guide ingredient selection
• Supports thoughtful formulation decisions
• Keeps our approach aligned with current nutrition research

Want to explore more?

👉 Learn more about how research informs our approach here.

Related articles

• What’s different with First Day products?

• Do your vitamins contain 100% Daily Value of nutrients?

• Are First Day vitamins FDA approved?

Nutrient Absorption and Bioavailability

• Department of Physiology, School of Medicine, Dokuz Eylul University, et al. - Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best

• Institute of Nutrition and Food Sciences, University of Bonn - Folic acid and L-5-methyltetrahydrofolate: comparison of clinical pharmacokinetics and pharmacodynamics

• Vitamin and Mineral Nutrition Laboratory, Beltsville Human Nutrition Research Center - The bioavailability to humans of ascorbic acid from oranges, orange juice and cooked broccoli is similar to that of synthetic ascorbic acid

• Institute of Human Nutrition Sciences, Warsaw University of Life Sciences - Tocopherols and Tocotrienols—Bioactive Dietary Compounds; What Is Certain, What Is Doubt?

• Cristiana Paul, MS and David M. Brady, ND, DC, CCN, DACBN - Comparative Bioavailability and Utilization of Particular Forms of B12 Supplements With Potential to Mitigate B12-related Genetic Polymorphisms

• Institute of Biochemistry, Life Sciences Center, Vilnius University - Bioavailability of Different Vitamin D Oral Supplements in Laboratory Animal Model

• Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Swiss Federal Institute of Technology - Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide

Micronutrient Function and Health

• Department of Pathology, University of Otago, et al. -Vitamin C and Immune Function

• Division of Nephrology, RWTH Aachen University - Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease

• University of Medical Sciences, Isfahan, Iran, et al. - Pyridoxal 5 Phosphate (P5P): Highly Bioavailable Vitamin B6

• Department of Molecular Biology, Pusan National University, et al. - Folic acid is necessary for proliferation and differentiation of C2C12 myoblasts

• National Institute of Health - Vitamin B1 (Thiamine)

• National Institute of Health - Riboflavin Fact Sheet for Health Professionals
  
• National Institute of Health - Biotin Fact Sheet Comparative Bioavailability and Utilization of Particular Forms of B12 Supplements With Potential to Mitigate B12-related Genetic Polymorphismsfor Health Professionals

Diet, Nutrition, and Public Health

• National Center for Chronic Disease Prevention and Health Promotion, et al. - Vital Signs: Fruit and Vegetable Intake Among Children — United States, 2003–2010

• Institute of Human Nutrition Sciences, Warsaw University of Life Sciences - Fruit and Vegetable Intake and Mental Health in Adults: A Systematic Review

• Program in International and Community Nutrition, Nutrition Department, University of California - The challenge to reach nutritional adequacy for vitamin A: β-carotene bioavailability and conversion--evidence in humans
  

• Austin J Cerebrovasc Dis Stroke - Sulforaphane Protects against Brain Diseases: Roles of Cytoprotective Enzymes