Vitamin D Deficiency Affects One in Three People

However, obtaining sufficient vitamin D through diet alone is challenging. The NHS recommends that everyone over age five consider taking a daily vitamin D supplement, especially during winter months. For children under five and individuals at risk of deficiency, supplementation is advised year-round.

Experts have raised concerns regarding routine vitamin D supplementation, particularly the risks associated with excessive intake. The NHS states that consuming more than 100 micrograms of vitamin D daily could be harmful. Since vitamin D is fat-soluble, it can accumulate in the body, potentially leading to toxicity and harming the heart, kidneys, and bones. It is crucial to monitor dosages, as many vitamin D supplements provide more than the necessary amount.

Supplements typically contain either vitamin D3 or D2. Bahee Van de Bor, a dietitian and spokesperson for the British Dietetic Association, notes that while both forms are well-absorbed, research indicates that vitamin D3 is absorbed more effectively. Vitamin D3, or cholecalciferol, is derived from animal sources and can also be synthesized by the skin, while D2, or ergocalciferol, is plant-based and suitable for those on plant-based diets.

The method of intake may be as important as the supplement type. Van de Bor suggests that vitamin D is best absorbed with a meal containing fat, indicating that individuals should take their supplement with any meal that fits into their routine.

This article is meant for general information and should not replace professional medical advice. Always consult a healthcare provider if health concerns arise. Originally published in January 2020, this information was updated in March 2026.