AFTER 40 · PRACTICAL WELLNESS

Vitamins after 40: start with a reason

A birthday alone does not establish a deficiency. Use your food intake, health history and clinical advice to decide what deserves attention.

Published November 7, 2026 · Source-researched by After 40 editorial. Not independently clinician-reviewed.

Vitamin D: a targeted conversation

Vitamin D supports calcium absorption and bone health. Some people need supplementation, but more is not automatically better and excess can be harmful. Ask whether your circumstances justify a test or a supplement, and count vitamin D already present in a multivitamin. Sun exposure is not a risk-free dosing strategy.

Vitamin B12: intake and absorption both matter

B12 deserves attention for people eating little or no animal-derived food and for some people with absorption problems or medicines that affect B12 status. Deficiency can cause important symptoms; fatigue alone cannot identify it. B12 is not an established energy booster when your status is already adequate.

Magnesium: food first, interactions matter

Nuts, seeds, beans and whole grains can contribute magnesium. Supplemental magnesium can cause diarrhea and can interact with medicines. Kidney problems can increase risk from excess. A product marketed for sleep does not demonstrate that everyone with poor sleep needs magnesium.

How to compare a supplement

Write down the exact ingredient, serving amount, intended reason, other products containing it and the total monthly cost. Bring the list to a clinician or pharmacist if you use medicines. Quality testing and evidence of benefit answer different questions.

Ordinary merchant links for comparison: iHerb offers a broad catalog; Life Extension has a large supplement range; Ritual offers multivitamin and other product lines; Thorne offers supplements across several categories. Compare the exact formulation and current delivered price. These companies are not interchangeable, and this is not a ranking or a recommendation to take all of them.

Use the printable label and cost checklist before choosing. Creatine and protein are different categories; our sister publication explains creatine and protein foods versus powder.

Read the source guidance

• NIH ODS: vitamin D ↗
• NIH ODS: vitamin B12 ↗
• NIH ODS: magnesium ↗
• FDA: supplement questions ↗