A growing number of Indians are suffering from a high level of Vitamin D deficiency, especially those living in states like Kerala and Tamil Nadu, a latest survey released on Wednesday said, highlighting the urgent need for greater preventive awareness, improved nutrition, and regular screening.

The survey, conducted among 22 lakh people across India, also found that teenagers have the highest incidence of Vitamin D deficiency. Interestingly, there is not much difference between men and women in terms of Vitamin D deficiency, the survey noted.

However, the data indicated a gradual improvement over time, with national deficiency rates declining from around 51% in 2019-20 to 43% in 2023-24.

Vitamin D is crucial as it regulates the amount of calcium and phosphate in the body. A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia or softening of the bones, in adults.

The alarming findings indicate that urban lifestyles, reduced sun exposure, and poor dietary habits - rather than geography alone  - are major contributors to Vitamin D deficiency in India.

The survey conducted by Metropolis Healthcare Limited, India’s second-largest pathology laboratory chain, revealed that between 2019 and 2025, 46.5% of individuals tested across India showed Vitamin D deficiency, while another 26% had insufficient levels, highlighting widespread Vitamin D inadequacy among health-seeking individuals.

The study revealed distinct differences across India. 

South India reported the highest deficiency at 51.6%, with Kerala, Puducherry, and Tamil Nadu each exceeding 50%.

Central India followed at 48.1%, while North India stood at 44.9%. 

West India, including Maharashtra (42.9%), showed better sufficiency levels, and the North-East (36.9%) recorded the lowest deficiency, reflecting the benefits of outdoor lifestyles and diverse diets.

Teenagers recorded the highest deficiency at 66.9%, pointing to a critical yet under-recognised health concern among India’s youth.

The gender gap in Vitamin D deficiency has narrowed over time, with women showing a 46.9% deficiency rate and men a 45.8% deficiency rate, indicating improved nutrition and diagnostic access among women, the survey added.

According to Surendran Chemmenkotil, Managing Director, Metropolis Healthcare Limited, “Vitamin D deficiency is one of the most overlooked health challenges in India today. Its effects are silent but far-reaching, impacting bone health, immunity, and overall well-being."

Dr Kirti Chadha, Chief Scientific and Innovation Officer, Metropolis Healthcare Limited, said: “Vitamin D plays a central role in bone mineralisation, muscle function, and immune regulation. Its deficiency often remains unnoticed until it leads to fatigue, weakness, or recurrent illness. Testing of calcium level and parathyroid hormone levels is crucial to arrive at a conclusive cause of Vitamin D deficiency/ insufficiency.”

On the declining Vitamin D rate in the past six years, the survey said, “While this trend is encouraging, the results reinforce the need for continued routine testing, nutritional interventions, and public awareness to prevent long-term health complications.”

According to experts, a person should get tested if they are showing symptoms like fatigue, muscle weakness, and depression. The causes behind deficiency include inadequate sun exposure and insufficient dietary intake, while treatment often involves supplements and fortified foods.