Micronutrient status of Indian population

Introduction

India has made tremendous progress in all fronts since independence including food production. Several programmes or schemes such as Integrated Child Development Services (ICDS) scheme, Mid-Day Meal Programme, National Iron Plus Initiative (NIPI), National Iodine Deficiency Disorders Control Programme (NIDDCP) and National Prophylaxis Programme against Nutritional Blindness due to Vitamin A Deficiency have also been launched over the years to improve the nutrition and health status of the population. However, still a large portion of the population suffers from malnutrition. According to the Food and Agriculture Organization report on State of Food Security and Nutrition in the World1, it is estimated that 190.7 million (14.5%) people were undernourished in India during 2014-2016.

Micronutrients though required in small amounts, are essential for proper growth and development of the human body2. Micronutrient deficiencies also referred to as ‘Hidden Hunger’ affects the health, learning ability as well as productivity owing to high rates of illness and disability contributing to vicious cycle of malnutrition, underdevelopment and poverty. It is estimated that around two billion people in the world are deficient in one or more micronutrients3. Micronutrient deficiencies (such as iodine, iron and vitamin A deficiency) not only affect the health but are also projected to cost around 0.8-2.5 per cent of the gross domestic product4. In India, around 0.5 per cent of total deaths in 2016 were contributed by nutritional deficiencies5.

National surveys such as National Family Health Survey (NFHS), National Nutrition Monitoring Bureau (NNMB), Annual Health Survey (AHS) and District Level Household Survey (DLHS) have been carried out to assess the health and nutrition status of the population in the country. The national surveys carried out have mainly focused on nutritional status based on anthropometric measurements, dietary intake and anaemia though independent surveys have been carried out to assess micronutrient deficiencies in the country. This review focuses on the current scenario of micronutrient status in the country covering national surveys as well as recent studies carried out. Studies on dietary intake have not been covered.

Iron, vitamin B₁₂, folate and ferritin deficiency

Anaemia is a major public health problem in the country as well as globally affecting nearly a third of the global population6. The National Nutritional Anaemia Prophylaxis Programme was launched in 1970 to prevent nutritional anaemia among children, expectant and nursing mothers as well as acceptors of family planning. The programme was later renamed in 1991 as National Nutritional Anaemia Control Programme targeting women in reproductive age group, especially pregnant and lactating women and preschool children7. The three strategies of the programme were promotion of regular consumption of foods rich in iron, provisions of iron and folate supplements in the form of tablets (folifer tablets) to the ‘high-risk’ groups and identification and treatment of severely anaemic cases8. In 2013, the Weekly Iron and Folic Acid Supplementation Programme was launched to reduce the prevalence and severity of nutritional anaemia among adolescents. Under this Programme, adolescents studying in class VI to XII from either government or government-aided or municipal schools as well as adolescent girls who are not in school are covered9. Subsequently, NIPI was launched in 2013 to prevent and control anaemia covering almost the entire age group, from infants six months onwards to women of reproductive age, providing weekly iron and folic acid (IFA) supplementation and deworming tablets administered twice a year, while daily dose of IFA tablet is being provided for 100 days during pregnancy as well as 100 days after delivery for lactating women10. However, more than half of the population still suffers from anaemia. As per the Global Burden of Disease Study 20165, iron-deficiency anaemia is among the top 10 causes of disability-adjusted life years for women. The latest National Family Health Survey (NFHS4) carried out by the Ministry of Health and Family Welfare reported the prevalence of anaemia as 58.6, 53.1, 50.4 and 22.7 per cent, respectively, among children aged 6-59 months, women aged 15-49 yr, pregnant women aged 15-49 yr and men aged 15-49 yr11.

Besides national surveys, various studies carried out in the country have also reported high burden of anaemia. A Task Force Study carried out by the Indian Council of Medical Research (ICMR), New Delhi, across 16 districts of 11 States among 11,260 pregnant women (n=6923) and adolescent girls (n=4337) also reported the prevalence of anaemia as 84.9 and 90.1 per cent, respectively12. The NNMB (ICMR) survey carried out in eight States also reported anaemia of around 67 to 78 per cent among preschool children, adolescent girls, pregnant and lactating women residing in the rural areas13. A study carried out among a cohort of pregnant women (n=72,750) residing in rural Maharashtra reported the prevalence of anaemia as 91 per cent14. A study carried out in rural Telangana among women aged 15-35 yr (n=979) reported lower prevalence of anaemia (28.4%) whereas prevalence of other micronutrient deficiencies such as ferritin (46.3%), folate (56.8%) and vitamin B₁₂ (44.4%) was reported to be around 50 per cent15.

Various initiatives taken by the Government of India have led to reduction in the prevalence of anaemia in the country (Figure). The prevalence of anaemia among preschool children has reduced in the past 16 yr by almost 16 per cent from 74.3 per cent during 1998-199916 to 58.5 per cent during 2015-201611. Similarly, DLHS surveys1819 have also shown reduction in anaemia among adolescent girls aged 10-19 yr by 41.3 per cent. A slight decrease (1.6%) in the prevalence of anaemia was also observed among men. Among ever married and pregnant women, not much improvement was observed compared to findings of NFHS-216; however, compared to findings of other surveys carried out after 2000, a reduction of 3-7 per cent was observed.

Close

Figure

Trend analysis of the prevalence of anaemia. Source: Refs 11, 16-20.

Export to PPT

Nutritional anaemia can be caused due to deficiencies of micronutrients such as iron, folic acid and vitamin B₁₂, with iron deficiency being the most common cause of anaemia. There is no nationwide data on status of these micronutrients; however, recent studies have highlighted that deficiencies still exist in the Indian population. With respect to vitamin B₁₂ deficiency, studies have indicated deficiency as high as 70-100 per cent (Table I). This may also be because about 29 per cent of the Indian population is vegetarian39. The prevalence of folate deficiency is not high as compared to vitamin B₁₂ deficiency; however, studies carried out in New Delhi and Maharashtra among preschool children and adolescents have indicated deficiency of around 40 to 60 per cent (Table II). Studies have reported the prevalence of low ferritin in almost 60 to 70 per cent of the population (Table III).

Vitamin A deficiency

The Government of India launched the National Prophylaxis Programme against Nutritional Blindness due to vitamin A deficiency in 1970 targeting children aged 1-6 yr with the specific aim of preventing nutritional blindness due to keratomalacia. The programme was modified in 1994, under the National Child Survival and Safe Motherhood Programme where the target group was restricted to 9-36 months children. The age of the target group was later modified as 6 to 59 months in 200642. As per NFHS-411, the percentage of children aged 9-59 months who received a vitamin A dose in the past six months has increased from 16.5 (2005-2006) to 60.2 per cent (2015-2016).

The multicentre study carried out by ICMR in 16 districts covering 1.64 lakh preschool children revealed the prevalence of vitamin A deficiency (Bitot's spots) as 0.83 per cent43. Another survey carried out by NNMB (ICMR) during 2002-2005 in eight States (Andhra Pradesh, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha, Tamil Nadu and West Bengal) reported similar prevalence of Bitot's spots (0.8%) among 71,591 rural preschool children44. Repeat surveys carried out by NNMB in seven States of the country covering rural preschool children have indicated reduction in the prevalence of vitamin A deficiency (Bitot's spots) from 0.7 (1996-1997) to 0.2 per cent (2011-2012)45. The Central India Children Eye Study carried out among 11829 schoolchildren of government schools in Nagpur, Maharashtra, reported the prevalence of Bitot's spots as 0.1 per cent46. The prevalence of Bitot's spots was also reported as 0.19 per cent among children 0-5 yr in Meghalaya47.

The prevalence of subclinical vitamin A deficiency (serum retinol <20 μg/dl) among preschool children was reported to be around 62 per cent as revealed by NNMB survey carried out during 2002-200548. A recent carried study carried out in Phek District of Nagaland covering 661 preschool children aged less than five years reported the prevalence of subclinical vitamin A deficiency as 32.6 per cent49. The prevalence of subclinical vitamin A deficiency (serum retinol <20 μg/dl) was reported as four per cent among tribal rural women of reproductive age in Central India38.

Iodine deficiency

The National Goitre Control Programme was launched by the Government of India in 1962 after successful demonstration of salt iodisation to control iodine-deficiency disorders (IDD) in Kangra Valley of Himachal Pradesh. The programme was later renamed as NIDDCP in 1992 focusing on universal salt iodisation. At present, sale of non-iodised salt for direct human consumption is banned under the Food Safety and Standards Act, 200650.

The initiatives taken by the Government has resulted in an increase in percentage of households (NFHS-2) using iodised salt, i.e., from 71.6 per cent during 1998-199916 to 93.1 per cent during 2015-201611. The National Iodine and Salt Intake Survey (2014-2015) also reported that 78 per cent of the households were consuming adequate iodised salt51.

Salt iodine content at the production and packaging site, wholesale and retail levels and in households; urinary iodine levels; thyroid-stimulating hormone (TSH) levels and change in goitre prevalence are indicators for monitoring and evaluating IDD control programmes52. In India, of the 414 districts surveyed so far up to the year 2015-2016, 337 districts were found to be endemic for IDD (total goitre rate >5%)53. However, NNMB survey carried out during 2002-2005 in eight States, i.e., Andhra Pradesh, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha, Tamil Nadu and West Bengal, reported total goitre rate of 3.9 per cent among schoolchildren44. Some of the recent surveys carried out in the country have reported total goitre rate of more than 5 per cent (Table IV). Further, median urinary iodine concentration, an indicator of current intake indicated adequate iodine intake among schoolchildren aged 6 yr and above (>100 μg/l) and non-pregnant women. A study carried out in Kangra, Himachal Pradesh, after 60 yr of salt iodisation also reported adequate iodine intake among schoolchildren aged 6-12 yr as indicated by median urinary iodine concentration of 200 μg/l, while total goitre rate was still more than 15 per cent66. Around 60 to 80 per cent neonates in Himachal Pradesh were also reported to be deficient in iodine (TSH >5 mUI/l)7677.

Insufficient iodine intake among pregnant women has been reported with median urinary iodine concentration of <150 μg/l5771727374. The ongoing Task Force Study on IDD by ICMR at 10 districts of the country would provide a better picture on the current status of iodine status among pregnant women.

Other micronutrient deficiencies

Limited studies have been carried out in the country to assess status of other micronutrients. Studies carried out to assess copper levels have reported deficiency of around 29 to 34 per cent among pregnant women and adult tribal population7879. Available literature on zinc levels has indicated high prevalence of zinc deficiency among children aged 6-60 months (43.8%), adolescents (49.4%) and pregnant women (64.6%)808182. Similarly, the prevalence of zinc deficiency has been reported to be around 52 to 58 per cent among tribal non-pregnant women in Central India38. While studies carried out among pregnant women in Assam (12%) and children aged six months to five years in Punjab (18%) reported lower prevalence of zinc deficiency7883, a recently published study84 projected that by 2050, the prevalence of zinc deficiency would increase by 2.9 per cent due to anthropogenic CO₂ emissions. Anthropogenic CO₂ emission disrupts the global climate system affecting food production and altering the nutrient profile of staple food crops and is likely to increase nutrient deficiencies.

Only few studies have also been carried out to assess vitamin C deficiency with plasma vitamin C as an indicator. The India age-related eye disease study carried out among the elderly aged 60 and above in north and south India reported the prevalence of vitamin C deficiency as 73.9 and 45.7 per cent, respectively85. Another study carried out among adolescent girls (n=775), residing in slums of New Delhi reported the prevalence of vitamin C deficiency as only 6.3 per cent86.

Conclusion

Micronutrient deficiency is a major health problem in the country, with anaemia affecting almost 50 to 60 per cent of the population while vitamin A deficiency and IDD have improved over the years. With recent initiatives of the government and strengthening existing health and agriculture systems, micronutrient status of the population is expected to improve in the coming years.