Should I be taking supplements at 40? An expert guide

January 6, 2026 •

5 min read

According to the National Institutes of Health, up to 30% of people over 50 may have difficulty absorbing vitamin B12 from food, a decline that can start in your 40s. This statistic highlights a key reason why many individuals in their fourth decade of life begin to question their nutritional strategy and whether supplements are necessary for maintaining health.

Quick Summary

As your body changes in your 40s, nutritional needs shift due to slowed metabolism, hormonal fluctuations, and reduced nutrient absorption. This guide explores which supplements, such as B12, vitamin D, and omega-3s, may be beneficial while emphasizing the primary role of diet and the necessity of consulting a doctor.

Key Points

Diet Is Primary, Supplements Are Secondary: Always prioritize a balanced, whole-food diet before relying on supplements to fill nutritional gaps.
Consult a Professional: Speak with a doctor or registered dietitian to assess your specific needs and avoid potential risks before starting any supplement.
Consider Age-Specific Needs: Certain nutrients like Vitamin B12, Vitamin D, and Calcium become increasingly important after 40 due to changes in absorption and bone density.
Understand Gender Differences: Men and women have unique requirements; for example, women need more support for bone health, while men may focus on prostate support.
Be Aware of Drug Interactions: Supplements can interfere with medications, so inform your healthcare provider about all products you are taking to prevent harmful interactions.
Look for Quality Assurance: Choose supplements tested and verified by third-party organizations like USP to ensure they contain what the label claims and are free of contaminants.

Why Your Nutritional Needs Change at 40

As you cross the threshold into your 40s, your body begins to undergo a series of subtle but significant physiological changes. These are natural parts of the aging process and directly impact your nutritional needs. A few key areas include:

Metabolism Slows Down

Around the age of 40, a gradual loss of muscle mass, known as sarcopenia, can begin. Since muscle tissue burns more calories than fat, this leads to a natural slowdown of your metabolism. This shift means that eating the same amount as you did in your 20s and 30s can result in weight gain. Therefore, your focus should shift to consuming highly nutrient-dense foods to ensure you get adequate vitamins and minerals from fewer calories.

Hormonal Shifts Occur

Hormonal changes affect both men and women. For women, perimenopause can start in the 40s, causing fluctuating estrogen levels that can impact bone density, mood, and fat storage. Men may experience a gradual decline in testosterone, which can affect muscle mass and energy levels. These shifts create a greater need for specific nutrients to support balance and mitigate symptoms.

Nutrient Absorption Decreases

Your body's ability to absorb certain nutrients from food can become less efficient with age. This is particularly true for vitamin B12, as a reduction in stomach acid production can hinder its absorption. This is why supplementation may become a more important consideration for older adults.

Key Supplements to Consider After 40

While a balanced diet is always the best source of nutrients, supplements can help fill gaps where deficiencies are common or absorption is less efficient. It is critical to consult a healthcare provider to determine your specific needs before beginning any supplement regimen.

Vitamin D

Often called the "sunshine vitamin," many people, including those over 40, are deficient in Vitamin D. It is crucial for calcium absorption, immune function, and bone health, especially for women as estrogen levels decline. Regular blood tests can help you determine the right dosage.

Vitamin B12

Given the age-related decline in absorption, B12 supplements are a strong consideration, particularly for vegetarians, vegans, or anyone over 40. Vitamin B12 is essential for nerve function, energy production, and red blood cell formation. Signs of deficiency include fatigue and cognitive fogginess.

Omega-3 Fatty Acids

Known for their anti-inflammatory properties, omega-3s (EPA and DHA) are vital for supporting heart and brain health, both of which are increased priorities after 40. They help lower triglycerides, support cardiovascular function, and may help with cognitive decline. If you don't eat fatty fish regularly, a supplement may be beneficial.

Calcium

With the natural decline in bone density, adequate calcium intake is a must for both men and women. However, it is especially critical for women in their 40s and beyond to prevent osteoporosis. The National Institute on Aging recommends different daily amounts for men and women after age 50.

Magnesium

Magnesium plays a role in hundreds of bodily processes, including blood sugar control, muscle function, and blood pressure regulation. Many people are deficient, and magnesium supplements may improve sleep quality and reduce muscle cramps, especially for those with active lifestyles.

Supplement Considerations: Men vs. Women over 40

While many supplements are beneficial for both genders, some age-related changes are sex-specific, warranting different considerations. A multivitamin formulated for your age and sex can be a good starting point.


Feature	Men Over 40	Women Over 40
Hormonal Change	Gradual testosterone decline.	Fluctuating estrogen, leading toward perimenopause.
Key Concern	Prostate health and muscle mass preservation.	Bone density loss and hormonal balance.
Primary Nutrients	Zinc, Saw Palmetto, CoQ10.	Calcium, Vitamin D, Evening Primrose Oil, Folic Acid.
Nutrient to Monitor	Avoid excess iron, as needs typically decrease.	Iron may still be necessary, depending on menstrual cycle.
Additional Support	May benefit from supplements for libido and energy, such as Tongkat Ali.	Can find relief for mood swings and skin health with supplements like Evening Primrose Oil.

Risks of Supplementation

Despite their potential benefits, supplements are not without risks. Since they are not as strictly regulated as prescription drugs, their quality can vary. It is essential to be aware of the following potential issues:

Overdosing

Believing that "more is better" can lead to consuming excessive amounts of certain vitamins and minerals, which can be toxic. For example, excessive Vitamin D can cause calcium buildup, and high doses of iron can be harmful.

Drug Interactions

Supplements can interfere with prescription medications. Vitamin K can reduce the effectiveness of blood thinners, and St. John's Wort can interact with antidepressants and heart medications. Always inform your doctor about every supplement you take.

Contamination and Mislabeling

Due to the lack of strict regulation, some supplements may contain unlisted ingredients, contaminants, or incorrect dosages. Looking for products with seals of approval from third-party testing organizations like USP or NSF can help.

The Power of Diet

Supplements should be seen as a complement to, not a replacement for, a healthy and balanced diet. A diet rich in whole foods provides a synergistic combination of nutrients that pills cannot replicate. Focus on these dietary strategies:

Prioritize Fiber: Add whole grains, nuts, seeds, and legumes to your diet to aid digestion, help manage cholesterol, and control blood sugar.
Eat the Rainbow: A variety of fruits and vegetables ensures you get a wide spectrum of antioxidants, vitamins, and minerals.
Choose Lean Proteins: Incorporate lean meats, fish, and plant-based proteins like chickpeas to maintain muscle mass.
Embrace Healthy Fats: Include avocados, olive oil, and nuts for heart and brain health.

Conclusion

As you reach 40, your body’s nutritional demands evolve, and supplementation may become a valuable part of your health strategy. Common areas of concern include bone health, energy levels, heart function, and cognitive performance, which can often be supported by vitamins like B12 and D, along with Omega-3s. However, the decision to take supplements should always be individualized and based on a discussion with a healthcare professional to assess your unique needs and potential risks. Pairing a targeted supplement plan with a consistently nutritious, whole-foods diet and regular exercise is the most effective approach to navigating your 40s and beyond with vitality. The National Institutes of Health (NIH) Office of Dietary Supplements provides valuable resources for further research on specific vitamins and minerals.

Frequently Asked Questions

A generic multivitamin can be a good starting point to cover basic needs but may not address the specific changes and common deficiencies that occur after 40, such as decreased B12 absorption. A targeted supplement based on blood tests and lifestyle may be more effective.

As you age, stomach acid production can decrease, which hinders the body's ability to absorb vitamin B12 from food. A supplement can provide the crystalline form of B12, which is more easily absorbed, ensuring adequate levels for nerve function and energy.

Omega-3s, particularly EPA and DHA, have anti-inflammatory properties that support heart and brain health, helping to mitigate the increased risk of chronic conditions like heart disease and cognitive decline that can accompany aging.

The biggest risk is the potential for harmful interactions with prescription medications. Supplements can alter how drugs are metabolized, either reducing their effectiveness or increasing side effects. There is also a risk of taking incorrect dosages.

Yes, they can have different needs. For example, women often require more calcium and vitamin D to combat bone density loss as they approach menopause, while men might focus on supplements like zinc or saw palmetto for prostate health.

While an optimal, nutrient-dense diet is the ideal foundation, it may not be enough. Age-related changes like reduced nutrient absorption can mean that even a good diet leaves gaps. Supplements can help bridge these gaps, but should not replace healthy eating.

Look for third-party verification seals on the product label from organizations like USP, NSF, or ConsumerLab.com. These seals indicate that the product has been tested for quality, potency, and purity.