Vitamin D and Muscle Strength in Older Adults

Vitamin D matters for your muscles, not just your bones: older adults with healthy vitamin D levels tend to be stronger, steadier on their feet and better at everyday physical tasks. It's one piece of nutrition after 60 I don't want anyone to overlook.

Does Vitamin D Affect Muscle Strength?

Yes, research links vitamin D to muscle strength, balance and physical performance. When we think about strength and fitness, most of us focus on movement, protein, and consistency. But there's one often-overlooked nutrient that quietly powers your progress: vitamin D.

Known as the "sunshine vitamin," vitamin D does a lot more than support bone health. It plays a critical role in muscle strength, balance, immune function, and even mood — all of which are essential for staying active and independent, especially as we age.

What Does the Research Say About Vitamin D and Strength?

Studies link adequate vitamin D to better strength, balance and physical function, though supplements haven't consistently prevented falls.

• Stronger muscles and better balance. A 2007 study published in the Journal of Gerontology found that older adults with adequate vitamin D levels had significantly better lower-body strength and balance compared to those who were deficient.
• Reduced risk of falls. According to a 2009 meta-analysis in BMJ, daily vitamin D supplementation of 700–1,000 IU reduced fall risk in older adults by 19%. Newer large trials, however, have not found fewer falls in healthy older adults living at home.
• Improved physical performance. A 2004 study in the American Journal of Clinical Nutrition showed that adults over 60 with higher vitamin D levels performed better in physical function tests — like walking speed and chair stands.
• Immune and mood support. Vitamin D receptors are found in immune cells and the brain. Studies suggest low levels are associated with increased risk of infections and depressive symptoms. This can affect your energy, motivation, and ability to stay consistent with movement.

How Do You Know If You're Low in Vitamin D?

The only way to know for sure is a blood test for 25(OH)D. Even in sunny climates, many adults — especially those over 50 — are low in vitamin D. Between indoor lifestyles, sunscreen, and reduced skin production with age, it's easy to fall below optimal levels.

What to do:

• Get your levels tested (look for 25(OH)D on a blood panel)
• Talk with your provider about the right blood level for you. The NIH considers 20 ng/mL or higher sufficient for most people.
• Supplement with D3 (often paired with K2) if needed — talk with your doctor about the right dose (I cover this more in my post on supplements over 60). The NIH upper limit for adults is 4,000 IU per day.
• Safely spend time outdoors when possible

What Foods Are High in Vitamin D?

Fatty fish like salmon, cod liver oil, UV-exposed mushrooms, egg yolks and fortified milk are some of the best food sources. While sunlight is a great source of vitamin D, certain foods can help support healthy levels — especially during the winter or if you avoid sun exposure.

Here are some top vitamin D–rich foods to add to your meals (vitamin D per serving):

• Wild-caught salmon (3.5 oz): 500–1,000 IU
• Sardines (2 small fish): ~50 IU
• Cod liver oil (1 tsp): ~450 IU
• Egg yolks (1 yolk): ~40–50 IU
• Mushrooms (UV-exposed): 300–400 IU
• Fortified milk (1 cup): ~100 IU
• Fortified orange juice (1 cup): ~100 IU

Tip: Look for UV-exposed mushrooms and pasture-raised eggs for higher natural vitamin D content. If your diet is limited or you're deficient, supplementation may still be necessary.

Vitamin D, Strength and Staying Independent

Vitamin D is more than a wellness trend — it's a foundational nutrient that supports your ability to move, recover, and stay independent. Optimizing this one piece can improve how your whole body functions, especially when you pair it with regular strength work, whether on your own or with in-home personal training.

Make sure your body, brain, and balance are supported from the inside out!