Low vitamin D in a sunny country: Why your level keeps dropping, even after the 60K sachets

Your annual health check comes back. Vitamin D: 14 ng/mL, flagged in red. Your doctor prescribes a 60,000 IU sachet once a week for eight weeks. You finish the course, the next report looks fine, and a year later the number has slid right back down. You live in one of the sunniest countries on earth. So what's going on?

You're not alone, and it isn't bad luck. It comes down to how your body makes vitamin D, when you're actually in the sun, and what happens after a big dose wears off.

Vitamin D is made in your skin, not on your plate

Most vitamins come from food. Vitamin D mostly doesn't. When UVB rays from the sun hit your skin, they turn a cholesterol-like compound into vitamin D3. [5] Your liver then converts it into 25-hydroxyvitamin D, the form your blood test measures, and your kidneys activate it when your body needs it.

Very few foods contain much vitamin D, especially in a mostly vegetarian Indian diet. So for most people, it's the sun or a supplement.

Why it matters:

• Bones: vitamin D helps your body absorb calcium, the raw material for strong bones. [9]
• Immune function: your immune cells carry vitamin D receptors, and some can activate vitamin D themselves. [4]

Sunny country, low vitamin D: the numbers

This isn't a few unlucky people. A review of 65 studies across South Asia found that 67% of adults in India were deficient. [1]

Closer to home, a study of 1,137 healthy 25 to 35-year-olds in Mumbai found an average level of 17.4 ng/mL, with 70% below 20 ng/mL. [2]

And your job matters. A review of 71 studies across many professions found that 78% of indoor workers were deficient, compared with 48% of outdoor workers. [3] The more of your day you spend under office lights, the less vitamin D your skin gets to make.

Why the sun isn't reaching your skin

1. You're indoors during the hours that count. In India, the UVB that makes vitamin D peaks between about 11 am and 2 pm, all year round. [6, 7] Morning and evening sun feels pleasant but carries much less UVB. For most professionals, those midday hours are spent in meetings.

2. Your skin needs longer. More melanin, sunscreen and covered-up clothing all cut how much vitamin D the skin makes from the same sunlight. [5] Indian skin needs more time in the sun than fair skin to make the same amount.

3. Smog filters the sun. In Delhi, children living in a heavily polluted area had less than half the vitamin D of children in a less polluted part of the city: 12.4 vs 27.1 ng/mL. [8]

4. North Indian winters barely count. In a winter study of schoolchildren in India, 30 minutes of midday sun a day for four weeks didn't raise their levels at all. [7] In November in Agra, the skin made almost no vitamin D. [5]

Reading your report: what the number means

The test is called 25-hydroxyvitamin D (sometimes "25-OH vitamin D"). Most Indian labs report it in ng/mL and use these bands, from the Endocrine Society's guideline: [9]

Your result	What labs usually call it
Below 20 ng/mL	Deficient
20 to 29 ng/mL	Insufficient
30 ng/mL and above	Sufficient

If your report uses nmol/L, divide by 2.5 to get ng/mL. Experts still debate the ideal target, so if your level is low, your doctor is the right person to set your dose.

Why your level slips after the sachets

The 60,000 IU sachets do their job: a large dose raises a low level quickly. The problem is what happens next.

The form of vitamin D your test measures has a half-life of about 15 days. [10] So after the last sachet, your level starts falling within weeks. In one trial of a single very large dose, levels peaked at one month and were already lower by three. [12] And nothing about your routine changed: you're still indoors at noon.

Bigger isn't automatically better either. In a trial of older adults, 60,000 IU once a month raised levels more than 24,000 IU, but the higher-dose group had more falls, not fewer. [13] And in Kashmir, doctors reported ten adults with vitamin D toxicity, all of whom had taken very high doses. [14]

"Think of the sachets as filling the tank. Daily vitamin D is what stops it from draining."

How to get more from every dose

Whatever you take, these four habits help more of it reach your blood.

1. Choose D3 over D2. A meta-analysis of head-to-head trials found that vitamin D3 raised blood levels more effectively than vitamin D2. [15] Check your label: D3 is often written as "cholecalciferol", D2 as "ergocalciferol".

2. Take it with a meal that has some fat. Vitamin D is fat-soluble. When people took it with a meal containing fat, 32% more was absorbed than with a fat-free meal. [16] In another study, people whose levels weren't rising on supplements switched to taking them with their largest meal, and their levels rose by about 50%. [17] Breakfast with eggs, paneer, curd or a little ghee works well.

3. Keep your magnesium up. The enzymes that convert vitamin D into the forms your body uses depend on magnesium. In a randomised trial, magnesium supplements helped bring vitamin D levels towards a healthy middle range. [18]

4. Take it every day. Steady daily intake keeps your level even, rather than rising and falling. [10, 11]

Where Drivon fits

Every serving of Drivon contains 600 IU of vitamin D3, the daily amount ICMR-NIN recommends for Indian adults. [19] It's a steady daily amount, not a megadose, designed for everyday use, not to replace a course your doctor prescribes.

Our D3 is plant-based, from lichen, rather than lanolin from sheep's wool, which is where most D3 comes from. It's taken once a day with breakfast or lunch, so it arrives with a meal, and it sits in the same capsule as magnesium aspartate. Vitamin D3 supports normal immune function and bone health, alongside Drivon's core four for a healthy stress response.

Frequently asked questions

Why is vitamin D deficiency so common in India?

Mostly timing and lifestyle. Your skin makes vitamin D mainly between 11 am and 2 pm, when most professionals are indoors. [6] Darker skin, covered clothing, sunscreen and pollution all cut how much the skin makes, and few Indian foods contain much vitamin D. [5, 8]

Is 600 IU of vitamin D3 a day enough?

600 IU is the daily amount ICMR-NIN recommends for Indian adults, meant to maintain healthy levels. [19] If your test shows you're deficient, your doctor may prescribe a higher dose first. A daily amount like 600 IU is what helps keep your level steady afterwards.

What is the best time to take vitamin D?

With a meal that contains some fat, at any time of day that you'll stick to. Fat in the meal increased absorption by 32%, and taking it with the largest meal raised levels by about 50% in people whose levels weren't rising. [16, 17]

Is D3 better than D2?

Yes, for raising blood levels. A meta-analysis of head-to-head trials found vitamin D3 raised blood levels more effectively than D2. [15] Check the label for "D3" or "cholecalciferol".

Is vitamin D3 from lichen the same as regular D3?

Yes, it's the same molecule, cholecalciferol. The difference is the source: most D3 is made from lanolin in sheep's wool, while lichen D3 is plant-based and suitable for vegetarians and vegans.

Can I take Drivon while on 60,000 IU sachets?

Ask your doctor first and add up your daily total. Drivon's 600 IU is a daily amount, designed for keeping levels steady rather than raising a deficient level.

Sources

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