What Age Should You Take Vitamin D? A Lifespan Guide

October 20, 2025 •

4 min read

Worldwide, vitamin D deficiency impacts more than 1 billion people, making it a major public health concern for all ages. Knowing what age should you take vitamin D is crucial, as the body's requirements for this essential nutrient vary significantly throughout your life, from infancy through older adulthood.

Quick Summary

This guide outlines the specific vitamin D needs for every life stage, from infancy and childhood to adulthood and senior years. It covers supplementation recommendations, potential deficiency risks, and the importance of this nutrient for strong bones and immune function.

Key Points

Infants need supplementation from birth: Healthcare providers recommend vitamin D supplementation for breastfed infants and formula-fed infants consuming less than adequate amounts of fortified formula/milk to prevent rickets.
Children require daily vitamin D for bone growth: The recommended daily intake for children and teens is essential for building strong bones during their growth years, as specified by health organizations.
Older adults often need more vitamin D: Individuals over 70 should aim for adequate daily intake, often a higher amount than younger adults, due to reduced skin synthesis and absorption, which helps combat bone loss and osteoporosis.
Individual needs vary: Factors like geography, skin pigmentation, body weight, and chronic health conditions can influence vitamin D requirements across all ages.
Testing provides clarity: A simple blood test can determine if you have a vitamin D deficiency or insufficiency, helping a healthcare provider recommend the right supplementation plan.
Excessive intake can be harmful: While important, too much vitamin D from supplements can lead to toxicity, which is why medical advice is crucial for determining appropriate amounts.

Vitamin D, often called the "sunshine vitamin," is a fat-soluble nutrient vital for numerous bodily functions, most notably for absorbing calcium and phosphorus for strong bones. While our bodies can produce vitamin D from sun exposure, dietary intake and supplementation are often necessary, especially during certain life stages. The appropriate timing and amount of vitamin D supplementation depend heavily on age, lifestyle, and individual health factors.

Vitamin D Needs for Infants (Birth to 12 Months)

All infants require a reliable source of vitamin D from birth, as breast milk typically does not contain enough to meet their needs. Healthcare providers often recommend vitamin D supplementation for infants.

Exclusively or Partially Breastfed Infants: Health authorities recommend vitamin D supplementation starting in the first few days of life. Supplementation should continue until the infant is weaned and consuming a sufficient amount of vitamin D-fortified formula or whole milk daily.
Formula-Fed Infants: If an infant is consuming a sufficient amount of vitamin D-fortified formula per day, additional supplementation is not necessary. If they consume less, they should receive a daily supplement as advised by a healthcare provider.
Signs of Deficiency: Severe deficiency can lead to rickets, a condition causing bone softening, bowed legs, and delayed walking. Other signs can include muscle spasms, seizures, and irritability.

Vitamin D Recommendations for Children and Adolescents (1 to 18 Years)

As children grow, their need for vitamin D increases to support continued bone development and overall health. Many children do not get enough vitamin D from diet and sunlight alone due to modern lifestyles.

Recommended Daily Intake: The recommended daily intake (RDI) for children and teens from 1 to 18 years old is generally specified by health organizations. This is crucial for maximizing bone health and preventing bone fractures.
Higher Risk Groups: Pediatricians may recommend supplementation for certain groups, including obese children, those with darker skin pigmentation, and those with chronic diseases like cystic fibrosis. Limited outdoor time also increases the risk of deficiency.
Deficiency Symptoms: In children, deficiency can cause bone pain, muscle aches, and developmental delays. Adolescents may experience pain in weight-bearing joints and can be misdiagnosed with conditions like depression due to vague symptoms.

Vitamin D for Adults (19 to 70 Years)

For most healthy adults, the RDI is typically outlined by health authorities. However, individual needs can vary based on factors like geographic location, skin tone, and lifestyle.

Sunlight Exposure: While skin can produce vitamin D from sun exposure, factors like living in northern latitudes, winter months, and regular sunscreen use can significantly limit production.
Dietary Sources: Adults can boost intake with foods like fatty fish (salmon, tuna), fortified dairy products, cereals, and orange juice.
Supplementation: Many adults may benefit from supplementation to ensure adequate levels, especially during months with limited sun exposure. A blood test can determine if supplementation is needed.

Vitamin D for Older Adults (71+ Years)

As we age, the skin's ability to synthesize vitamin D from sunlight decreases, and the kidneys become less efficient at converting it to its active form. This puts older adults at a higher risk of deficiency.

Increased RDI: The RDI for adults over 70 is often higher to support bone health and reduce fracture risk.
Calcium Co-management: Vitamin D is critical for calcium absorption, so adequate intake is vital for protecting against osteoporosis, a condition characterized by thinning bones.

Comparison Table: Vitamin D Needs by Age Group


Life Stage	Recommended Daily Amount (RDA/AI)	Common Supplementation Need	Primary Risk Factors for Deficiency
Infants (0-12 months)	As specified by health authorities	All breastfed infants, formula-fed infants consuming less than adequate amounts of fortified formula/milk	Exclusive breastfeeding, low sun exposure
Children (1-13 years)	As specified by health authorities	Common due to limited sun exposure and dietary gaps	Limited sun exposure, picky eating, darker skin
Teens (14-18 years)	As specified by health authorities	Common due to lifestyle factors, dietary gaps	Sedentary lifestyle, obesity, darker skin
Adults (19-70 years)	As specified by health authorities	Often needed during winter months or for those with limited sun	Limited sun exposure, northern latitudes, certain medical conditions
Older Adults (71+ years)	Often a higher amount than younger adults, as specified by health authorities	High likelihood due to reduced skin synthesis and absorption	Reduced skin production, decreased sun exposure, poor absorption

Special Considerations for Supplementation

Pregnancy and Breastfeeding: Pregnant and breastfeeding individuals should aim for adequate vitamin D daily, as low levels in the mother can affect the newborn.
Chronic Health Conditions: Individuals with conditions affecting fat absorption, such as Crohn's disease or celiac disease, may require supplementation as they have difficulty absorbing fat-soluble vitamins. Chronic liver or kidney disease can also interfere with vitamin D metabolism.
Obesity: Obese individuals may have lower circulating levels of vitamin D and may require supplementation. This is because vitamin D can be stored in body fat, making less available for use.

Testing and Monitoring Vitamin D Levels

To determine an individual's specific needs, a blood test can measure the level of 25-hydroxy vitamin D in the blood. A healthcare provider can recommend an appropriate testing and treatment plan based on these results and other risk factors. It is important to note that while supplementation is vital for many, excessive intake can lead to vitamin D toxicity, so it should be monitored carefully, especially at higher amounts.

Conclusion: Personalized Needs Across the Lifespan

In conclusion, there is no single right answer to the question of what age should you take vitamin D, as the need for supplementation varies by life stage and individual circumstances. Infants, children, and older adults have specific guidelines to ensure they receive adequate amounts for bone development and maintenance. Many healthy adults can meet their needs through sun exposure and diet, but supplementation becomes more important in the winter or with limited sun exposure. Consulting a healthcare provider for a personalized plan is the most effective way to ensure optimal vitamin D levels throughout life.

For more detailed information on nutrient guidelines, a good resource is the NIH Office of Dietary Supplements website.

Frequently Asked Questions

Maybe. Your body makes vitamin D from sun exposure, but many factors affect production, including time of day, season, geographic location, and sunscreen use. A blood test can determine if your sun exposure and diet are providing enough vitamin D.

Few foods are naturally rich in vitamin D, but some of the best dietary sources include fatty fish like salmon and trout, cod liver oil, and fortified foods such as milk, cereal, and some orange juices.

Yes, taking excessively high doses of vitamin D supplements can be harmful and lead to vitamin D toxicity. This can cause excess calcium in the blood, leading to symptoms like confusion, vomiting, and potential kidney damage.

Symptoms can be subtle and non-specific. They may include fatigue, bone pain, muscle weakness, mood changes like depression, and an increased risk of bone fractures.

Yes, vitamin D supplementation is recommended and safe for all breastfed infants from birth. For formula-fed babies, it's typically needed if they consume less than an adequate amount of fortified formula per day.

Yes. People with darker skin pigmentation have higher amounts of melanin, which acts as a natural sunscreen and reduces the skin's ability to produce vitamin D from sunlight. This increases the risk of deficiency and may require supplementation.

Yes, heavier children typically require consideration for supplementation. The vitamin can be stored in body fat, potentially reducing its availability in the bloodstream and bones, where it is needed most.