Why Vitamin D Supplements Can Make You Feel Worse

Despite widespread apply to treat deficiency, vitamin D supplements can sometimes lead to unpleasant side effects. Nutrition experts warn that feeling unwell or experiencing pain after starting vitamin D supplementation may indicate an imbalance within the body.

The Calcium Connection

According to Morgan Walker, MS, RD, a registered dietitian at Lebanon Valley College, a primary cause of these symptoms is elevated calcium levels in the blood. Vitamin D plays a crucial role in regulating calcium absorption and high doses – whether taken for extended periods or even in moderate amounts by sensitive individuals – can disrupt this balance .

Symptoms of Excess Calcium

Signs of too much calcium, also known as hypercalcemia, can include:

• Nausea
• Constipation
• Fatigue
• Muscle weakness
• Headache
• Increased thirst and urination
• “Mental fog”

In severe cases, hypercalcemia can lead to heart rhythm disturbances or kidney problems .

The Role of Magnesium

Magnesium deficiency can exacerbate the negative effects of excess vitamin D. The body requires magnesium to properly metabolize vitamin D, and a lack of it can contribute to symptoms like muscle spasms and sleep disturbances.

Beyond Vitamin D: Potential Allergies

Feeling unwell immediately after taking a vitamin D supplement might not be due to the vitamin itself, but rather an allergy to other ingredients in the capsule, such as soybean, coconut, or corn oil.

What to Do If You Experience Symptoms

If you experience any of these symptoms after starting vitamin D supplementation, it’s advisable to temporarily stop taking the supplement and consult with a healthcare professional. Blood tests can help determine your vitamin D levels and assess related elements like calcium and magnesium.

Safe Dosage and Long-Term Use

It’s generally recommended not to exceed a daily dose of 4,000 international units (IU) of vitamin D without medical supervision. Excessive intake increases the risk of side effects .

Boosting Vitamin D Levels Naturally

While supplementation can be helpful, there are also natural ways to increase vitamin D levels, including safe sun exposure and consuming vitamin D-rich foods .