India has a paradox that surprises most people when they hear it. Despite being one of the sunniest countries in the world, Vitamin D deficiency affects an estimated 70–90% of the population. For older adults, the numbers are worse.
If your doctor has recently told you your Vitamin D is low, or you suspect it might be, here is what that actually means — and what to do about it.
What Vitamin D Actually Does
Vitamin D is often described as a bone vitamin, which undersells it considerably. It does support calcium absorption and bone density — that much is widely known. But it also modulates immune function, supports muscle strength (low Vitamin D is associated with increased fall risk in older adults), is involved in mood regulation, and plays a role in cardiovascular health.
Calling it a bone vitamin is like calling the internet a messaging service. Accurate, but incomplete.
Why Seniors in India Are Especially Vulnerable
Reduced outdoor exposure. Older adults in India, particularly women, often spend limited time in direct sunlight — a combination of cultural norms around sun avoidance, reduced mobility, and the heat that makes outdoor activity difficult for much of the year.
Skin efficiency declines with age. The skin’s capacity to synthesise Vitamin D from UV radiation decreases with age. A 70-year-old produces roughly four times less Vitamin D from the same sun exposure as a 20-year-old.
Kidney conversion drops. Vitamin D from sun or food must be converted in the liver and then the kidneys into its active form. Kidney function declines with age, and this conversion becomes less efficient.
Medication depletion. Corticosteroids (used for arthritis, asthma, and autoimmune conditions) reduce Vitamin D metabolism. Certain antiepileptic medications do the same.
Darker skin. Melanin in darker skin acts as a natural UV filter, which means more sun exposure is needed to produce the same amount of Vitamin D. This is a meaningful factor in a population where deficiency is already widespread.
Symptoms That Often Get Misattributed
Vitamin D deficiency is a slow-developing condition. Its symptoms are non-specific enough that they are regularly attributed to ageing, overwork, or other conditions:
Fatigue that is not explained by sleep quality. Bone pain or tenderness, particularly in the lower back, hips, and legs. Muscle weakness and increased risk of falls. Low mood or mild depression. Frequent infections.
None of these symptoms alone confirm deficiency — a blood test does. But if several of these are present, Vitamin D is worth checking.
What a Vitamin D Supplement Looks Like
D3, not D2. Cholecalciferol (D3) raises blood levels of Vitamin D more effectively and sustains them longer than ergocalciferol (D2). Most quality supplements use D3.
Take it with fat. Vitamin D is fat-soluble. Taken on an empty stomach or with a fat-free meal, it is poorly absorbed. Take it with your largest meal of the day — lunch or dinner with some oil, ghee, nuts, or dairy is sufficient.
Dosage depends on your starting level. Without a blood test, a maintenance dose of 1,000–2,000 IU daily is a reasonable starting point for adults over 55. Higher corrective doses (5,000 IU or above) are sometimes used to address severe deficiency and should be guided by a test result and a doctor.
Toxicity is real but rare. Vitamin D toxicity requires prolonged supplementation at very high doses (generally above 10,000 IU daily for extended periods). At standard supplemental doses, it is not a concern. However, Vitamin D is fat-soluble and does accumulate, which is why megadosing without a test is not advisable.
Testing and Monitoring
The test you want is a 25-hydroxyvitamin D blood test, sometimes written as 25(OH)D. Most pathology labs in India offer it; it is not expensive.
General reference ranges classify levels below 20 ng/mL as deficient, 20–30 ng/mL as insufficient, and above 30 ng/mL as sufficient. Many functional medicine practitioners aim for 40–60 ng/mL as an optimal range for adults.
If you are starting a supplement and want to know whether your full nutritional picture — not just Vitamin D — has gaps worth addressing, HelioCoach’s free Nutrient Gap Analyser flags likely deficiencies based on your diet, lifestyle, medications, and symptoms.
